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deparse.c
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1/*-------------------------------------------------------------------------
2 *
3 * deparse.c
4 * Query deparser for postgres_fdw
5 *
6 * This file includes functions that examine query WHERE clauses to see
7 * whether they're safe to send to the remote server for execution, as
8 * well as functions to construct the query text to be sent. The latter
9 * functionality is annoyingly duplicative of ruleutils.c, but there are
10 * enough special considerations that it seems best to keep this separate.
11 * One saving grace is that we only need deparse logic for node types that
12 * we consider safe to send.
13 *
14 * We assume that the remote session's search_path is exactly "pg_catalog",
15 * and thus we need schema-qualify all and only names outside pg_catalog.
16 *
17 * We do not consider that it is ever safe to send COLLATE expressions to
18 * the remote server: it might not have the same collation names we do.
19 * (Later we might consider it safe to send COLLATE "C", but even that would
20 * fail on old remote servers.) An expression is considered safe to send
21 * only if all operator/function input collations used in it are traceable to
22 * Var(s) of the foreign table. That implies that if the remote server gets
23 * a different answer than we do, the foreign table's columns are not marked
24 * with collations that match the remote table's columns, which we can
25 * consider to be user error.
26 *
27 * Portions Copyright (c) 2012-2025, PostgreSQL Global Development Group
28 *
29 * IDENTIFICATION
30 * contrib/postgres_fdw/deparse.c
31 *
32 *-------------------------------------------------------------------------
33 */
34#include "postgres.h"
35
36#include "access/htup_details.h"
37#include "access/sysattr.h"
38#include "access/table.h"
39#include "catalog/pg_aggregate.h"
40#include "catalog/pg_authid.h"
41#include "catalog/pg_collation.h"
42#include "catalog/pg_database.h"
43#include "catalog/pg_namespace.h"
44#include "catalog/pg_operator.h"
45#include "catalog/pg_opfamily.h"
46#include "catalog/pg_proc.h"
47#include "catalog/pg_ts_config.h"
48#include "catalog/pg_ts_dict.h"
49#include "catalog/pg_type.h"
50#include "commands/defrem.h"
51#include "nodes/nodeFuncs.h"
52#include "nodes/plannodes.h"
53#include "optimizer/optimizer.h"
54#include "optimizer/prep.h"
55#include "optimizer/tlist.h"
56#include "parser/parsetree.h"
57#include "postgres_fdw.h"
58#include "utils/builtins.h"
59#include "utils/lsyscache.h"
60#include "utils/rel.h"
61#include "utils/syscache.h"
62#include "utils/typcache.h"
63
64/*
65 * Global context for foreign_expr_walker's search of an expression tree.
66 */
67typedef struct foreign_glob_cxt
68{
69 PlannerInfo *root; /* global planner state */
70 RelOptInfo *foreignrel; /* the foreign relation we are planning for */
71 Relids relids; /* relids of base relations in the underlying
72 * scan */
73} foreign_glob_cxt;
74
75/*
76 * Local (per-tree-level) context for foreign_expr_walker's search.
77 * This is concerned with identifying collations used in the expression.
78 */
79typedef enum
80{
81 FDW_COLLATE_NONE, /* expression is of a noncollatable type, or
82 * it has default collation that is not
83 * traceable to a foreign Var */
84 FDW_COLLATE_SAFE, /* collation derives from a foreign Var */
85 FDW_COLLATE_UNSAFE, /* collation is non-default and derives from
86 * something other than a foreign Var */
87} FDWCollateState;
88
89typedef struct foreign_loc_cxt
90{
91 Oid collation; /* OID of current collation, if any */
92 FDWCollateState state; /* state of current collation choice */
93} foreign_loc_cxt;
94
95/*
96 * Context for deparseExpr
97 */
98typedef struct deparse_expr_cxt
99{
100 PlannerInfo *root; /* global planner state */
101 RelOptInfo *foreignrel; /* the foreign relation we are planning for */
102 RelOptInfo *scanrel; /* the underlying scan relation. Same as
103 * foreignrel, when that represents a join or
104 * a base relation. */
105 StringInfo buf; /* output buffer to append to */
106 List **params_list; /* exprs that will become remote Params */
107} deparse_expr_cxt;
108
109#define REL_ALIAS_PREFIX "r"
110/* Handy macro to add relation name qualification */
111#define ADD_REL_QUALIFIER(buf, varno) \
112 appendStringInfo((buf), "%s%d.", REL_ALIAS_PREFIX, (varno))
113#define SUBQUERY_REL_ALIAS_PREFIX "s"
114#define SUBQUERY_COL_ALIAS_PREFIX "c"
115
116/*
117 * Functions to determine whether an expression can be evaluated safely on
118 * remote server.
119 */
120static bool foreign_expr_walker(Node *node,
121 foreign_glob_cxt *glob_cxt,
122 foreign_loc_cxt *outer_cxt,
123 foreign_loc_cxt *case_arg_cxt);
124static char *deparse_type_name(Oid type_oid, int32 typemod);
125
126/*
127 * Functions to construct string representation of a node tree.
128 */
129static void deparseTargetList(StringInfo buf,
130 RangeTblEntry *rte,
131 Index rtindex,
132 Relation rel,
133 bool is_returning,
134 Bitmapset *attrs_used,
135 bool qualify_col,
136 List **retrieved_attrs);
137static void deparseExplicitTargetList(List *tlist,
138 bool is_returning,
139 List **retrieved_attrs,
140 deparse_expr_cxt *context);
141static void deparseSubqueryTargetList(deparse_expr_cxt *context);
142static void deparseReturningList(StringInfo buf, RangeTblEntry *rte,
143 Index rtindex, Relation rel,
144 bool trig_after_row,
145 List *withCheckOptionList,
146 List *returningList,
147 List **retrieved_attrs);
148static void deparseColumnRef(StringInfo buf, int varno, int varattno,
149 RangeTblEntry *rte, bool qualify_col);
150static void deparseRelation(StringInfo buf, Relation rel);
151static void deparseExpr(Expr *node, deparse_expr_cxt *context);
152static void deparseVar(Var *node, deparse_expr_cxt *context);
153static void deparseConst(Const *node, deparse_expr_cxt *context, int showtype);
154static void deparseParam(Param *node, deparse_expr_cxt *context);
155static void deparseSubscriptingRef(SubscriptingRef *node, deparse_expr_cxt *context);
156static void deparseFuncExpr(FuncExpr *node, deparse_expr_cxt *context);
157static void deparseOpExpr(OpExpr *node, deparse_expr_cxt *context);
158static bool isPlainForeignVar(Expr *node, deparse_expr_cxt *context);
159static void deparseOperatorName(StringInfo buf, Form_pg_operator opform);
160static void deparseDistinctExpr(DistinctExpr *node, deparse_expr_cxt *context);
161static void deparseScalarArrayOpExpr(ScalarArrayOpExpr *node,
162 deparse_expr_cxt *context);
163static void deparseRelabelType(RelabelType *node, deparse_expr_cxt *context);
164static void deparseArrayCoerceExpr(ArrayCoerceExpr *node, deparse_expr_cxt *context);
165static void deparseBoolExpr(BoolExpr *node, deparse_expr_cxt *context);
166static void deparseNullTest(NullTest *node, deparse_expr_cxt *context);
167static void deparseCaseExpr(CaseExpr *node, deparse_expr_cxt *context);
168static void deparseArrayExpr(ArrayExpr *node, deparse_expr_cxt *context);
169static void printRemoteParam(int paramindex, Oid paramtype, int32 paramtypmod,
170 deparse_expr_cxt *context);
171static void printRemotePlaceholder(Oid paramtype, int32 paramtypmod,
172 deparse_expr_cxt *context);
173static void deparseSelectSql(List *tlist, bool is_subquery, List **retrieved_attrs,
174 deparse_expr_cxt *context);
175static void deparseLockingClause(deparse_expr_cxt *context);
176static void appendOrderByClause(List *pathkeys, bool has_final_sort,
177 deparse_expr_cxt *context);
178static void appendLimitClause(deparse_expr_cxt *context);
179static void appendConditions(List *exprs, deparse_expr_cxt *context);
180static void deparseFromExprForRel(StringInfo buf, PlannerInfo *root,
181 RelOptInfo *foreignrel, bool use_alias,
182 Index ignore_rel, List **ignore_conds,
183 List **additional_conds,
184 List **params_list);
185static void appendWhereClause(List *exprs, List *additional_conds,
186 deparse_expr_cxt *context);
187static void deparseFromExpr(List *quals, deparse_expr_cxt *context);
188static void deparseRangeTblRef(StringInfo buf, PlannerInfo *root,
189 RelOptInfo *foreignrel, bool make_subquery,
190 Index ignore_rel, List **ignore_conds,
191 List **additional_conds, List **params_list);
192static void deparseAggref(Aggref *node, deparse_expr_cxt *context);
193static void appendGroupByClause(List *tlist, deparse_expr_cxt *context);
194static void appendOrderBySuffix(Oid sortop, Oid sortcoltype, bool nulls_first,
195 deparse_expr_cxt *context);
196static void appendAggOrderBy(List *orderList, List *targetList,
197 deparse_expr_cxt *context);
198static void appendFunctionName(Oid funcid, deparse_expr_cxt *context);
199static Node *deparseSortGroupClause(Index ref, List *tlist, bool force_colno,
200 deparse_expr_cxt *context);
201
202/*
203 * Helper functions
204 */
205static bool is_subquery_var(Var *node, RelOptInfo *foreignrel,
206 int *relno, int *colno);
207static void get_relation_column_alias_ids(Var *node, RelOptInfo *foreignrel,
208 int *relno, int *colno);
209
210
211/*
212 * Examine each qual clause in input_conds, and classify them into two groups,
213 * which are returned as two lists:
214 * - remote_conds contains expressions that can be evaluated remotely
215 * - local_conds contains expressions that can't be evaluated remotely
216 */
217void
218classifyConditions(PlannerInfo *root,
219 RelOptInfo *baserel,
220 List *input_conds,
221 List **remote_conds,
222 List **local_conds)
223{
224 ListCell *lc;
225
226 *remote_conds = NIL;
227 *local_conds = NIL;
228
229 foreach(lc, input_conds)
230 {
231 RestrictInfo *ri = lfirst_node(RestrictInfo, lc);
232
233 if (is_foreign_expr(root, baserel, ri->clause))
234 *remote_conds = lappend(*remote_conds, ri);
235 else
236 *local_conds = lappend(*local_conds, ri);
237 }
238}
239
240/*
241 * Returns true if given expr is safe to evaluate on the foreign server.
242 */
243bool
244is_foreign_expr(PlannerInfo *root,
245 RelOptInfo *baserel,
246 Expr *expr)
247{
248 foreign_glob_cxt glob_cxt;
249 foreign_loc_cxt loc_cxt;
250 PgFdwRelationInfo *fpinfo = (PgFdwRelationInfo *) (baserel->fdw_private);
251
252 /*
253 * Check that the expression consists of nodes that are safe to execute
254 * remotely.
255 */
256 glob_cxt.root = root;
257 glob_cxt.foreignrel = baserel;
258
259 /*
260 * For an upper relation, use relids from its underneath scan relation,
261 * because the upperrel's own relids currently aren't set to anything
262 * meaningful by the core code. For other relation, use their own relids.
263 */
264 if (IS_UPPER_REL(baserel))
265 glob_cxt.relids = fpinfo->outerrel->relids;
266 else
267 glob_cxt.relids = baserel->relids;
268 loc_cxt.collation = InvalidOid;
269 loc_cxt.state = FDW_COLLATE_NONE;
270 if (!foreign_expr_walker((Node *) expr, &glob_cxt, &loc_cxt, NULL))
271 return false;
272
273 /*
274 * If the expression has a valid collation that does not arise from a
275 * foreign var, the expression can not be sent over.
276 */
277 if (loc_cxt.state == FDW_COLLATE_UNSAFE)
278 return false;
279
280 /*
281 * An expression which includes any mutable functions can't be sent over
282 * because its result is not stable. For example, sending now() remote
283 * side could cause confusion from clock offsets. Future versions might
284 * be able to make this choice with more granularity. (We check this last
285 * because it requires a lot of expensive catalog lookups.)
286 */
287 if (contain_mutable_functions((Node *) expr))
288 return false;
289
290 /* OK to evaluate on the remote server */
291 return true;
292}
293
294/*
295 * Check if expression is safe to execute remotely, and return true if so.
296 *
297 * In addition, *outer_cxt is updated with collation information.
298 *
299 * case_arg_cxt is NULL if this subexpression is not inside a CASE-with-arg.
300 * Otherwise, it points to the collation info derived from the arg expression,
301 * which must be consulted by any CaseTestExpr.
302 *
303 * We must check that the expression contains only node types we can deparse,
304 * that all types/functions/operators are safe to send (they are "shippable"),
305 * and that all collations used in the expression derive from Vars of the
306 * foreign table. Because of the latter, the logic is pretty close to
307 * assign_collations_walker() in parse_collate.c, though we can assume here
308 * that the given expression is valid. Note function mutability is not
309 * currently considered here.
310 */
311static bool
312foreign_expr_walker(Node *node,
313 foreign_glob_cxt *glob_cxt,
314 foreign_loc_cxt *outer_cxt,
315 foreign_loc_cxt *case_arg_cxt)
316{
317 bool check_type = true;
318 PgFdwRelationInfo *fpinfo;
319 foreign_loc_cxt inner_cxt;
320 Oid collation;
321 FDWCollateState state;
322
323 /* Need do nothing for empty subexpressions */
324 if (node == NULL)
325 return true;
326
327 /* May need server info from baserel's fdw_private struct */
328 fpinfo = (PgFdwRelationInfo *) (glob_cxt->foreignrel->fdw_private);
329
330 /* Set up inner_cxt for possible recursion to child nodes */
331 inner_cxt.collation = InvalidOid;
332 inner_cxt.state = FDW_COLLATE_NONE;
333
334 switch (nodeTag(node))
335 {
336 case T_Var:
337 {
338 Var *var = (Var *) node;
339
340 /*
341 * If the Var is from the foreign table, we consider its
342 * collation (if any) safe to use. If it is from another
343 * table, we treat its collation the same way as we would a
344 * Param's collation, ie it's not safe for it to have a
345 * non-default collation.
346 */
347 if (bms_is_member(var->varno, glob_cxt->relids) &&
348 var->varlevelsup == 0)
349 {
350 /* Var belongs to foreign table */
351
352 /*
353 * System columns other than ctid should not be sent to
354 * the remote, since we don't make any effort to ensure
355 * that local and remote values match (tableoid, in
356 * particular, almost certainly doesn't match).
357 */
358 if (var->varattno < 0 &&
359 var->varattno != SelfItemPointerAttributeNumber)
360 return false;
361
362 /* Else check the collation */
363 collation = var->varcollid;
364 state = OidIsValid(collation) ? FDW_COLLATE_SAFE : FDW_COLLATE_NONE;
365 }
366 else
367 {
368 /* Var belongs to some other table */
369 collation = var->varcollid;
370 if (collation == InvalidOid ||
371 collation == DEFAULT_COLLATION_OID)
372 {
373 /*
374 * It's noncollatable, or it's safe to combine with a
375 * collatable foreign Var, so set state to NONE.
376 */
377 state = FDW_COLLATE_NONE;
378 }
379 else
380 {
381 /*
382 * Do not fail right away, since the Var might appear
383 * in a collation-insensitive context.
384 */
385 state = FDW_COLLATE_UNSAFE;
386 }
387 }
388 }
389 break;
390 case T_Const:
391 {
392 Const *c = (Const *) node;
393
394 /*
395 * Constants of regproc and related types can't be shipped
396 * unless the referenced object is shippable. But NULL's ok.
397 * (See also the related code in dependency.c.)
398 */
399 if (!c->constisnull)
400 {
401 switch (c->consttype)
402 {
403 case REGPROCOID:
404 case REGPROCEDUREOID:
405 if (!is_shippable(DatumGetObjectId(c->constvalue),
406 ProcedureRelationId, fpinfo))
407 return false;
408 break;
409 case REGOPEROID:
410 case REGOPERATOROID:
411 if (!is_shippable(DatumGetObjectId(c->constvalue),
412 OperatorRelationId, fpinfo))
413 return false;
414 break;
415 case REGCLASSOID:
416 if (!is_shippable(DatumGetObjectId(c->constvalue),
417 RelationRelationId, fpinfo))
418 return false;
419 break;
420 case REGTYPEOID:
421 if (!is_shippable(DatumGetObjectId(c->constvalue),
422 TypeRelationId, fpinfo))
423 return false;
424 break;
425 case REGCOLLATIONOID:
426 if (!is_shippable(DatumGetObjectId(c->constvalue),
427 CollationRelationId, fpinfo))
428 return false;
429 break;
430 case REGCONFIGOID:
431
432 /*
433 * For text search objects only, we weaken the
434 * normal shippability criterion to allow all OIDs
435 * below FirstNormalObjectId. Without this, none
436 * of the initdb-installed TS configurations would
437 * be shippable, which would be quite annoying.
438 */
439 if (DatumGetObjectId(c->constvalue) >= FirstNormalObjectId &&
440 !is_shippable(DatumGetObjectId(c->constvalue),
441 TSConfigRelationId, fpinfo))
442 return false;
443 break;
444 case REGDICTIONARYOID:
445 if (DatumGetObjectId(c->constvalue) >= FirstNormalObjectId &&
446 !is_shippable(DatumGetObjectId(c->constvalue),
447 TSDictionaryRelationId, fpinfo))
448 return false;
449 break;
450 case REGNAMESPACEOID:
451 if (!is_shippable(DatumGetObjectId(c->constvalue),
452 NamespaceRelationId, fpinfo))
453 return false;
454 break;
455 case REGROLEOID:
456 if (!is_shippable(DatumGetObjectId(c->constvalue),
457 AuthIdRelationId, fpinfo))
458 return false;
459 break;
460 case REGDATABASEOID:
461 if (!is_shippable(DatumGetObjectId(c->constvalue),
462 DatabaseRelationId, fpinfo))
463 return false;
464 break;
465 }
466 }
467
468 /*
469 * If the constant has nondefault collation, either it's of a
470 * non-builtin type, or it reflects folding of a CollateExpr.
471 * It's unsafe to send to the remote unless it's used in a
472 * non-collation-sensitive context.
473 */
474 collation = c->constcollid;
475 if (collation == InvalidOid ||
476 collation == DEFAULT_COLLATION_OID)
477 state = FDW_COLLATE_NONE;
478 else
479 state = FDW_COLLATE_UNSAFE;
480 }
481 break;
482 case T_Param:
483 {
484 Param *p = (Param *) node;
485
486 /*
487 * If it's a MULTIEXPR Param, punt. We can't tell from here
488 * whether the referenced sublink/subplan contains any remote
489 * Vars; if it does, handling that is too complicated to
490 * consider supporting at present. Fortunately, MULTIEXPR
491 * Params are not reduced to plain PARAM_EXEC until the end of
492 * planning, so we can easily detect this case. (Normal
493 * PARAM_EXEC Params are safe to ship because their values
494 * come from somewhere else in the plan tree; but a MULTIEXPR
495 * references a sub-select elsewhere in the same targetlist,
496 * so we'd be on the hook to evaluate it somehow if we wanted
497 * to handle such cases as direct foreign updates.)
498 */
499 if (p->paramkind == PARAM_MULTIEXPR)
500 return false;
501
502 /*
503 * Collation rule is same as for Consts and non-foreign Vars.
504 */
505 collation = p->paramcollid;
506 if (collation == InvalidOid ||
507 collation == DEFAULT_COLLATION_OID)
508 state = FDW_COLLATE_NONE;
509 else
510 state = FDW_COLLATE_UNSAFE;
511 }
512 break;
513 case T_SubscriptingRef:
514 {
515 SubscriptingRef *sr = (SubscriptingRef *) node;
516
517 /* Assignment should not be in restrictions. */
518 if (sr->refassgnexpr != NULL)
519 return false;
520
521 /*
522 * Recurse into the remaining subexpressions. The container
523 * subscripts will not affect collation of the SubscriptingRef
524 * result, so do those first and reset inner_cxt afterwards.
525 */
526 if (!foreign_expr_walker((Node *) sr->refupperindexpr,
527 glob_cxt, &inner_cxt, case_arg_cxt))
528 return false;
529 inner_cxt.collation = InvalidOid;
530 inner_cxt.state = FDW_COLLATE_NONE;
531 if (!foreign_expr_walker((Node *) sr->reflowerindexpr,
532 glob_cxt, &inner_cxt, case_arg_cxt))
533 return false;
534 inner_cxt.collation = InvalidOid;
535 inner_cxt.state = FDW_COLLATE_NONE;
536 if (!foreign_expr_walker((Node *) sr->refexpr,
537 glob_cxt, &inner_cxt, case_arg_cxt))
538 return false;
539
540 /*
541 * Container subscripting typically yields same collation as
542 * refexpr's, but in case it doesn't, use same logic as for
543 * function nodes.
544 */
545 collation = sr->refcollid;
546 if (collation == InvalidOid)
547 state = FDW_COLLATE_NONE;
548 else if (inner_cxt.state == FDW_COLLATE_SAFE &&
549 collation == inner_cxt.collation)
550 state = FDW_COLLATE_SAFE;
551 else if (collation == DEFAULT_COLLATION_OID)
552 state = FDW_COLLATE_NONE;
553 else
554 state = FDW_COLLATE_UNSAFE;
555 }
556 break;
557 case T_FuncExpr:
558 {
559 FuncExpr *fe = (FuncExpr *) node;
560
561 /*
562 * If function used by the expression is not shippable, it
563 * can't be sent to remote because it might have incompatible
564 * semantics on remote side.
565 */
566 if (!is_shippable(fe->funcid, ProcedureRelationId, fpinfo))
567 return false;
568
569 /*
570 * Recurse to input subexpressions.
571 */
572 if (!foreign_expr_walker((Node *) fe->args,
573 glob_cxt, &inner_cxt, case_arg_cxt))
574 return false;
575
576 /*
577 * If function's input collation is not derived from a foreign
578 * Var, it can't be sent to remote.
579 */
580 if (fe->inputcollid == InvalidOid)
581 /* OK, inputs are all noncollatable */ ;
582 else if (inner_cxt.state != FDW_COLLATE_SAFE ||
583 fe->inputcollid != inner_cxt.collation)
584 return false;
585
586 /*
587 * Detect whether node is introducing a collation not derived
588 * from a foreign Var. (If so, we just mark it unsafe for now
589 * rather than immediately returning false, since the parent
590 * node might not care.)
591 */
592 collation = fe->funccollid;
593 if (collation == InvalidOid)
594 state = FDW_COLLATE_NONE;
595 else if (inner_cxt.state == FDW_COLLATE_SAFE &&
596 collation == inner_cxt.collation)
597 state = FDW_COLLATE_SAFE;
598 else if (collation == DEFAULT_COLLATION_OID)
599 state = FDW_COLLATE_NONE;
600 else
601 state = FDW_COLLATE_UNSAFE;
602 }
603 break;
604 case T_OpExpr:
605 case T_DistinctExpr: /* struct-equivalent to OpExpr */
606 {
607 OpExpr *oe = (OpExpr *) node;
608
609 /*
610 * Similarly, only shippable operators can be sent to remote.
611 * (If the operator is shippable, we assume its underlying
612 * function is too.)
613 */
614 if (!is_shippable(oe->opno, OperatorRelationId, fpinfo))
615 return false;
616
617 /*
618 * Recurse to input subexpressions.
619 */
620 if (!foreign_expr_walker((Node *) oe->args,
621 glob_cxt, &inner_cxt, case_arg_cxt))
622 return false;
623
624 /*
625 * If operator's input collation is not derived from a foreign
626 * Var, it can't be sent to remote.
627 */
628 if (oe->inputcollid == InvalidOid)
629 /* OK, inputs are all noncollatable */ ;
630 else if (inner_cxt.state != FDW_COLLATE_SAFE ||
631 oe->inputcollid != inner_cxt.collation)
632 return false;
633
634 /* Result-collation handling is same as for functions */
635 collation = oe->opcollid;
636 if (collation == InvalidOid)
637 state = FDW_COLLATE_NONE;
638 else if (inner_cxt.state == FDW_COLLATE_SAFE &&
639 collation == inner_cxt.collation)
640 state = FDW_COLLATE_SAFE;
641 else if (collation == DEFAULT_COLLATION_OID)
642 state = FDW_COLLATE_NONE;
643 else
644 state = FDW_COLLATE_UNSAFE;
645 }
646 break;
647 case T_ScalarArrayOpExpr:
648 {
649 ScalarArrayOpExpr *oe = (ScalarArrayOpExpr *) node;
650
651 /*
652 * Again, only shippable operators can be sent to remote.
653 */
654 if (!is_shippable(oe->opno, OperatorRelationId, fpinfo))
655 return false;
656
657 /*
658 * Recurse to input subexpressions.
659 */
660 if (!foreign_expr_walker((Node *) oe->args,
661 glob_cxt, &inner_cxt, case_arg_cxt))
662 return false;
663
664 /*
665 * If operator's input collation is not derived from a foreign
666 * Var, it can't be sent to remote.
667 */
668 if (oe->inputcollid == InvalidOid)
669 /* OK, inputs are all noncollatable */ ;
670 else if (inner_cxt.state != FDW_COLLATE_SAFE ||
671 oe->inputcollid != inner_cxt.collation)
672 return false;
673
674 /* Output is always boolean and so noncollatable. */
675 collation = InvalidOid;
676 state = FDW_COLLATE_NONE;
677 }
678 break;
679 case T_RelabelType:
680 {
681 RelabelType *r = (RelabelType *) node;
682
683 /*
684 * Recurse to input subexpression.
685 */
686 if (!foreign_expr_walker((Node *) r->arg,
687 glob_cxt, &inner_cxt, case_arg_cxt))
688 return false;
689
690 /*
691 * RelabelType must not introduce a collation not derived from
692 * an input foreign Var (same logic as for a real function).
693 */
694 collation = r->resultcollid;
695 if (collation == InvalidOid)
696 state = FDW_COLLATE_NONE;
697 else if (inner_cxt.state == FDW_COLLATE_SAFE &&
698 collation == inner_cxt.collation)
699 state = FDW_COLLATE_SAFE;
700 else if (collation == DEFAULT_COLLATION_OID)
701 state = FDW_COLLATE_NONE;
702 else
703 state = FDW_COLLATE_UNSAFE;
704 }
705 break;
706 case T_ArrayCoerceExpr:
707 {
708 ArrayCoerceExpr *e = (ArrayCoerceExpr *) node;
709
710 /*
711 * Recurse to input subexpression.
712 */
713 if (!foreign_expr_walker((Node *) e->arg,
714 glob_cxt, &inner_cxt, case_arg_cxt))
715 return false;
716
717 /*
718 * T_ArrayCoerceExpr must not introduce a collation not
719 * derived from an input foreign Var (same logic as for a
720 * function).
721 */
722 collation = e->resultcollid;
723 if (collation == InvalidOid)
724 state = FDW_COLLATE_NONE;
725 else if (inner_cxt.state == FDW_COLLATE_SAFE &&
726 collation == inner_cxt.collation)
727 state = FDW_COLLATE_SAFE;
728 else if (collation == DEFAULT_COLLATION_OID)
729 state = FDW_COLLATE_NONE;
730 else
731 state = FDW_COLLATE_UNSAFE;
732 }
733 break;
734 case T_BoolExpr:
735 {
736 BoolExpr *b = (BoolExpr *) node;
737
738 /*
739 * Recurse to input subexpressions.
740 */
741 if (!foreign_expr_walker((Node *) b->args,
742 glob_cxt, &inner_cxt, case_arg_cxt))
743 return false;
744
745 /* Output is always boolean and so noncollatable. */
746 collation = InvalidOid;
747 state = FDW_COLLATE_NONE;
748 }
749 break;
750 case T_NullTest:
751 {
752 NullTest *nt = (NullTest *) node;
753
754 /*
755 * Recurse to input subexpressions.
756 */
757 if (!foreign_expr_walker((Node *) nt->arg,
758 glob_cxt, &inner_cxt, case_arg_cxt))
759 return false;
760
761 /* Output is always boolean and so noncollatable. */
762 collation = InvalidOid;
763 state = FDW_COLLATE_NONE;
764 }
765 break;
766 case T_CaseExpr:
767 {
768 CaseExpr *ce = (CaseExpr *) node;
769 foreign_loc_cxt arg_cxt;
770 foreign_loc_cxt tmp_cxt;
771 ListCell *lc;
772
773 /*
774 * Recurse to CASE's arg expression, if any. Its collation
775 * has to be saved aside for use while examining CaseTestExprs
776 * within the WHEN expressions.
777 */
778 arg_cxt.collation = InvalidOid;
779 arg_cxt.state = FDW_COLLATE_NONE;
780 if (ce->arg)
781 {
782 if (!foreign_expr_walker((Node *) ce->arg,
783 glob_cxt, &arg_cxt, case_arg_cxt))
784 return false;
785 }
786
787 /* Examine the CaseWhen subexpressions. */
788 foreach(lc, ce->args)
789 {
790 CaseWhen *cw = lfirst_node(CaseWhen, lc);
791
792 if (ce->arg)
793 {
794 /*
795 * In a CASE-with-arg, the parser should have produced
796 * WHEN clauses of the form "CaseTestExpr = RHS",
797 * possibly with an implicit coercion inserted above
798 * the CaseTestExpr. However in an expression that's
799 * been through the optimizer, the WHEN clause could
800 * be almost anything (since the equality operator
801 * could have been expanded into an inline function).
802 * In such cases forbid pushdown, because
803 * deparseCaseExpr can't handle it.
804 */
805 Node *whenExpr = (Node *) cw->expr;
806 List *opArgs;
807
808 if (!IsA(whenExpr, OpExpr))
809 return false;
810
811 opArgs = ((OpExpr *) whenExpr)->args;
812 if (list_length(opArgs) != 2 ||
813 !IsA(strip_implicit_coercions(linitial(opArgs)),
814 CaseTestExpr))
815 return false;
816 }
817
818 /*
819 * Recurse to WHEN expression, passing down the arg info.
820 * Its collation doesn't affect the result (really, it
821 * should be boolean and thus not have a collation).
822 */
823 tmp_cxt.collation = InvalidOid;
824 tmp_cxt.state = FDW_COLLATE_NONE;
825 if (!foreign_expr_walker((Node *) cw->expr,
826 glob_cxt, &tmp_cxt, &arg_cxt))
827 return false;
828
829 /* Recurse to THEN expression. */
830 if (!foreign_expr_walker((Node *) cw->result,
831 glob_cxt, &inner_cxt, case_arg_cxt))
832 return false;
833 }
834
835 /* Recurse to ELSE expression. */
836 if (!foreign_expr_walker((Node *) ce->defresult,
837 glob_cxt, &inner_cxt, case_arg_cxt))
838 return false;
839
840 /*
841 * Detect whether node is introducing a collation not derived
842 * from a foreign Var. (If so, we just mark it unsafe for now
843 * rather than immediately returning false, since the parent
844 * node might not care.) This is the same as for function
845 * nodes, except that the input collation is derived from only
846 * the THEN and ELSE subexpressions.
847 */
848 collation = ce->casecollid;
849 if (collation == InvalidOid)
850 state = FDW_COLLATE_NONE;
851 else if (inner_cxt.state == FDW_COLLATE_SAFE &&
852 collation == inner_cxt.collation)
853 state = FDW_COLLATE_SAFE;
854 else if (collation == DEFAULT_COLLATION_OID)
855 state = FDW_COLLATE_NONE;
856 else
857 state = FDW_COLLATE_UNSAFE;
858 }
859 break;
860 case T_CaseTestExpr:
861 {
862 CaseTestExpr *c = (CaseTestExpr *) node;
863
864 /* Punt if we seem not to be inside a CASE arg WHEN. */
865 if (!case_arg_cxt)
866 return false;
867
868 /*
869 * Otherwise, any nondefault collation attached to the
870 * CaseTestExpr node must be derived from foreign Var(s) in
871 * the CASE arg.
872 */
873 collation = c->collation;
874 if (collation == InvalidOid)
875 state = FDW_COLLATE_NONE;
876 else if (case_arg_cxt->state == FDW_COLLATE_SAFE &&
877 collation == case_arg_cxt->collation)
878 state = FDW_COLLATE_SAFE;
879 else if (collation == DEFAULT_COLLATION_OID)
880 state = FDW_COLLATE_NONE;
881 else
882 state = FDW_COLLATE_UNSAFE;
883 }
884 break;
885 case T_ArrayExpr:
886 {
887 ArrayExpr *a = (ArrayExpr *) node;
888
889 /*
890 * Recurse to input subexpressions.
891 */
892 if (!foreign_expr_walker((Node *) a->elements,
893 glob_cxt, &inner_cxt, case_arg_cxt))
894 return false;
895
896 /*
897 * ArrayExpr must not introduce a collation not derived from
898 * an input foreign Var (same logic as for a function).
899 */
900 collation = a->array_collid;
901 if (collation == InvalidOid)
902 state = FDW_COLLATE_NONE;
903 else if (inner_cxt.state == FDW_COLLATE_SAFE &&
904 collation == inner_cxt.collation)
905 state = FDW_COLLATE_SAFE;
906 else if (collation == DEFAULT_COLLATION_OID)
907 state = FDW_COLLATE_NONE;
908 else
909 state = FDW_COLLATE_UNSAFE;
910 }
911 break;
912 case T_List:
913 {
914 List *l = (List *) node;
915 ListCell *lc;
916
917 /*
918 * Recurse to component subexpressions.
919 */
920 foreach(lc, l)
921 {
922 if (!foreign_expr_walker((Node *) lfirst(lc),
923 glob_cxt, &inner_cxt, case_arg_cxt))
924 return false;
925 }
926
927 /*
928 * When processing a list, collation state just bubbles up
929 * from the list elements.
930 */
931 collation = inner_cxt.collation;
932 state = inner_cxt.state;
933
934 /* Don't apply exprType() to the list. */
935 check_type = false;
936 }
937 break;
938 case T_Aggref:
939 {
940 Aggref *agg = (Aggref *) node;
941 ListCell *lc;
942
943 /* Not safe to pushdown when not in grouping context */
944 if (!IS_UPPER_REL(glob_cxt->foreignrel))
945 return false;
946
947 /* Only non-split aggregates are pushable. */
948 if (agg->aggsplit != AGGSPLIT_SIMPLE)
949 return false;
950
951 /* As usual, it must be shippable. */
952 if (!is_shippable(agg->aggfnoid, ProcedureRelationId, fpinfo))
953 return false;
954
955 /*
956 * Recurse to input args. aggdirectargs, aggorder and
957 * aggdistinct are all present in args, so no need to check
958 * their shippability explicitly.
959 */
960 foreach(lc, agg->args)
961 {
962 Node *n = (Node *) lfirst(lc);
963
964 /* If TargetEntry, extract the expression from it */
965 if (IsA(n, TargetEntry))
966 {
967 TargetEntry *tle = (TargetEntry *) n;
968
969 n = (Node *) tle->expr;
970 }
971
972 if (!foreign_expr_walker(n,
973 glob_cxt, &inner_cxt, case_arg_cxt))
974 return false;
975 }
976
977 /*
978 * For aggorder elements, check whether the sort operator, if
979 * specified, is shippable or not.
980 */
981 if (agg->aggorder)
982 {
983 foreach(lc, agg->aggorder)
984 {
985 SortGroupClause *srt = (SortGroupClause *) lfirst(lc);
986 Oid sortcoltype;
987 TypeCacheEntry *typentry;
988 TargetEntry *tle;
989
990 tle = get_sortgroupref_tle(srt->tleSortGroupRef,
991 agg->args);
992 sortcoltype = exprType((Node *) tle->expr);
993 typentry = lookup_type_cache(sortcoltype,
994 TYPECACHE_LT_OPR | TYPECACHE_GT_OPR);
995 /* Check shippability of non-default sort operator. */
996 if (srt->sortop != typentry->lt_opr &&
997 srt->sortop != typentry->gt_opr &&
998 !is_shippable(srt->sortop, OperatorRelationId,
999 fpinfo))
1000 return false;
1001 }
1002 }
1003
1004 /* Check aggregate filter */
1005 if (!foreign_expr_walker((Node *) agg->aggfilter,
1006 glob_cxt, &inner_cxt, case_arg_cxt))
1007 return false;
1008
1009 /*
1010 * If aggregate's input collation is not derived from a
1011 * foreign Var, it can't be sent to remote.
1012 */
1013 if (agg->inputcollid == InvalidOid)
1014 /* OK, inputs are all noncollatable */ ;
1015 else if (inner_cxt.state != FDW_COLLATE_SAFE ||
1016 agg->inputcollid != inner_cxt.collation)
1017 return false;
1018
1019 /*
1020 * Detect whether node is introducing a collation not derived
1021 * from a foreign Var. (If so, we just mark it unsafe for now
1022 * rather than immediately returning false, since the parent
1023 * node might not care.)
1024 */
1025 collation = agg->aggcollid;
1026 if (collation == InvalidOid)
1027 state = FDW_COLLATE_NONE;
1028 else if (inner_cxt.state == FDW_COLLATE_SAFE &&
1029 collation == inner_cxt.collation)
1030 state = FDW_COLLATE_SAFE;
1031 else if (collation == DEFAULT_COLLATION_OID)
1032 state = FDW_COLLATE_NONE;
1033 else
1034 state = FDW_COLLATE_UNSAFE;
1035 }
1036 break;
1037 default:
1038
1039 /*
1040 * If it's anything else, assume it's unsafe. This list can be
1041 * expanded later, but don't forget to add deparse support below.
1042 */
1043 return false;
1044 }
1045
1046 /*
1047 * If result type of given expression is not shippable, it can't be sent
1048 * to remote because it might have incompatible semantics on remote side.
1049 */
1050 if (check_type && !is_shippable(exprType(node), TypeRelationId, fpinfo))
1051 return false;
1052
1053 /*
1054 * Now, merge my collation information into my parent's state.
1055 */
1056 if (state > outer_cxt->state)
1057 {
1058 /* Override previous parent state */
1059 outer_cxt->collation = collation;
1060 outer_cxt->state = state;
1061 }
1062 else if (state == outer_cxt->state)
1063 {
1064 /* Merge, or detect error if there's a collation conflict */
1065 switch (state)
1066 {
1067 case FDW_COLLATE_NONE:
1068 /* Nothing + nothing is still nothing */
1069 break;
1070 case FDW_COLLATE_SAFE:
1071 if (collation != outer_cxt->collation)
1072 {
1073 /*
1074 * Non-default collation always beats default.
1075 */
1076 if (outer_cxt->collation == DEFAULT_COLLATION_OID)
1077 {
1078 /* Override previous parent state */
1079 outer_cxt->collation = collation;
1080 }
1081 else if (collation != DEFAULT_COLLATION_OID)
1082 {
1083 /*
1084 * Conflict; show state as indeterminate. We don't
1085 * want to "return false" right away, since parent
1086 * node might not care about collation.
1087 */
1088 outer_cxt->state = FDW_COLLATE_UNSAFE;
1089 }
1090 }
1091 break;
1092 case FDW_COLLATE_UNSAFE:
1093 /* We're still conflicted ... */
1094 break;
1095 }
1096 }
1097
1098 /* It looks OK */
1099 return true;
1100}
1101
1102/*
1103 * Returns true if given expr is something we'd have to send the value of
1104 * to the foreign server.
1105 *
1106 * This should return true when the expression is a shippable node that
1107 * deparseExpr would add to context->params_list. Note that we don't care
1108 * if the expression *contains* such a node, only whether one appears at top
1109 * level. We need this to detect cases where setrefs.c would recognize a
1110 * false match between an fdw_exprs item (which came from the params_list)
1111 * and an entry in fdw_scan_tlist (which we're considering putting the given
1112 * expression into).
1113 */
1114bool
1115is_foreign_param(PlannerInfo *root,
1116 RelOptInfo *baserel,
1117 Expr *expr)
1118{
1119 if (expr == NULL)
1120 return false;
1121
1122 switch (nodeTag(expr))
1123 {
1124 case T_Var:
1125 {
1126 /* It would have to be sent unless it's a foreign Var */
1127 Var *var = (Var *) expr;
1128 PgFdwRelationInfo *fpinfo = (PgFdwRelationInfo *) (baserel->fdw_private);
1129 Relids relids;
1130
1131 if (IS_UPPER_REL(baserel))
1132 relids = fpinfo->outerrel->relids;
1133 else
1134 relids = baserel->relids;
1135
1136 if (bms_is_member(var->varno, relids) && var->varlevelsup == 0)
1137 return false; /* foreign Var, so not a param */
1138 else
1139 return true; /* it'd have to be a param */
1140 break;
1141 }
1142 case T_Param:
1143 /* Params always have to be sent to the foreign server */
1144 return true;
1145 default:
1146 break;
1147 }
1148 return false;
1149}
1150
1151/*
1152 * Returns true if it's safe to push down the sort expression described by
1153 * 'pathkey' to the foreign server.
1154 */
1155bool
1156is_foreign_pathkey(PlannerInfo *root,
1157 RelOptInfo *baserel,
1158 PathKey *pathkey)
1159{
1160 EquivalenceClass *pathkey_ec = pathkey->pk_eclass;
1161 PgFdwRelationInfo *fpinfo = (PgFdwRelationInfo *) baserel->fdw_private;
1162
1163 /*
1164 * is_foreign_expr would detect volatile expressions as well, but checking
1165 * ec_has_volatile here saves some cycles.
1166 */
1167 if (pathkey_ec->ec_has_volatile)
1168 return false;
1169
1170 /* can't push down the sort if the pathkey's opfamily is not shippable */
1171 if (!is_shippable(pathkey->pk_opfamily, OperatorFamilyRelationId, fpinfo))
1172 return false;
1173
1174 /* can push if a suitable EC member exists */
1175 return (find_em_for_rel(root, pathkey_ec, baserel) != NULL);
1176}
1177
1178/*
1179 * Convert type OID + typmod info into a type name we can ship to the remote
1180 * server. Someplace else had better have verified that this type name is
1181 * expected to be known on the remote end.
1182 *
1183 * This is almost just format_type_with_typemod(), except that if left to its
1184 * own devices, that function will make schema-qualification decisions based
1185 * on the local search_path, which is wrong. We must schema-qualify all
1186 * type names that are not in pg_catalog. We assume here that built-in types
1187 * are all in pg_catalog and need not be qualified; otherwise, qualify.
1188 */
1189static char *
1190deparse_type_name(Oid type_oid, int32 typemod)
1191{
1192 bits16 flags = FORMAT_TYPE_TYPEMOD_GIVEN;
1193
1194 if (!is_builtin(type_oid))
1195 flags |= FORMAT_TYPE_FORCE_QUALIFY;
1196
1197 return format_type_extended(type_oid, typemod, flags);
1198}
1199
1200/*
1201 * Build the targetlist for given relation to be deparsed as SELECT clause.
1202 *
1203 * The output targetlist contains the columns that need to be fetched from the
1204 * foreign server for the given relation. If foreignrel is an upper relation,
1205 * then the output targetlist can also contain expressions to be evaluated on
1206 * foreign server.
1207 */
1208List *
1209build_tlist_to_deparse(RelOptInfo *foreignrel)
1210{
1211 List *tlist = NIL;
1212 PgFdwRelationInfo *fpinfo = (PgFdwRelationInfo *) foreignrel->fdw_private;
1213 ListCell *lc;
1214
1215 /*
1216 * For an upper relation, we have already built the target list while
1217 * checking shippability, so just return that.
1218 */
1219 if (IS_UPPER_REL(foreignrel))
1220 return fpinfo->grouped_tlist;
1221
1222 /*
1223 * We require columns specified in foreignrel->reltarget->exprs and those
1224 * required for evaluating the local conditions.
1225 */
1226 tlist = add_to_flat_tlist(tlist,
1227 pull_var_clause((Node *) foreignrel->reltarget->exprs,
1228 PVC_RECURSE_PLACEHOLDERS));
1229 foreach(lc, fpinfo->local_conds)
1230 {
1231 RestrictInfo *rinfo = lfirst_node(RestrictInfo, lc);
1232
1233 tlist = add_to_flat_tlist(tlist,
1234 pull_var_clause((Node *) rinfo->clause,
1235 PVC_RECURSE_PLACEHOLDERS));
1236 }
1237
1238 return tlist;
1239}
1240
1241/*
1242 * Deparse SELECT statement for given relation into buf.
1243 *
1244 * tlist contains the list of desired columns to be fetched from foreign server.
1245 * For a base relation fpinfo->attrs_used is used to construct SELECT clause,
1246 * hence the tlist is ignored for a base relation.
1247 *
1248 * remote_conds is the list of conditions to be deparsed into the WHERE clause
1249 * (or, in the case of upper relations, into the HAVING clause).
1250 *
1251 * If params_list is not NULL, it receives a list of Params and other-relation
1252 * Vars used in the clauses; these values must be transmitted to the remote
1253 * server as parameter values.
1254 *
1255 * If params_list is NULL, we're generating the query for EXPLAIN purposes,
1256 * so Params and other-relation Vars should be replaced by dummy values.
1257 *
1258 * pathkeys is the list of pathkeys to order the result by.
1259 *
1260 * is_subquery is the flag to indicate whether to deparse the specified
1261 * relation as a subquery.
1262 *
1263 * List of columns selected is returned in retrieved_attrs.
1264 */
1265void
1266deparseSelectStmtForRel(StringInfo buf, PlannerInfo *root, RelOptInfo *rel,
1267 List *tlist, List *remote_conds, List *pathkeys,
1268 bool has_final_sort, bool has_limit, bool is_subquery,
1269 List **retrieved_attrs, List **params_list)
1270{
1271 deparse_expr_cxt context;
1272 PgFdwRelationInfo *fpinfo = (PgFdwRelationInfo *) rel->fdw_private;
1273 List *quals;
1274
1275 /*
1276 * We handle relations for foreign tables, joins between those and upper
1277 * relations.
1278 */
1279 Assert(IS_JOIN_REL(rel) || IS_SIMPLE_REL(rel) || IS_UPPER_REL(rel));
1280
1281 /* Fill portions of context common to upper, join and base relation */
1282 context.buf = buf;
1283 context.root = root;
1284 context.foreignrel = rel;
1285 context.scanrel = IS_UPPER_REL(rel) ? fpinfo->outerrel : rel;
1286 context.params_list = params_list;
1287
1288 /* Construct SELECT clause */
1289 deparseSelectSql(tlist, is_subquery, retrieved_attrs, &context);
1290
1291 /*
1292 * For upper relations, the WHERE clause is built from the remote
1293 * conditions of the underlying scan relation; otherwise, we can use the
1294 * supplied list of remote conditions directly.
1295 */
1296 if (IS_UPPER_REL(rel))
1297 {
1298 PgFdwRelationInfo *ofpinfo;
1299
1300 ofpinfo = (PgFdwRelationInfo *) fpinfo->outerrel->fdw_private;
1301 quals = ofpinfo->remote_conds;
1302 }
1303 else
1304 quals = remote_conds;
1305
1306 /* Construct FROM and WHERE clauses */
1307 deparseFromExpr(quals, &context);
1308
1309 if (IS_UPPER_REL(rel))
1310 {
1311 /* Append GROUP BY clause */
1312 appendGroupByClause(tlist, &context);
1313
1314 /* Append HAVING clause */
1315 if (remote_conds)
1316 {
1317 appendStringInfoString(buf, " HAVING ");
1318 appendConditions(remote_conds, &context);
1319 }
1320 }
1321
1322 /* Add ORDER BY clause if we found any useful pathkeys */
1323 if (pathkeys)
1324 appendOrderByClause(pathkeys, has_final_sort, &context);
1325
1326 /* Add LIMIT clause if necessary */
1327 if (has_limit)
1328 appendLimitClause(&context);
1329
1330 /* Add any necessary FOR UPDATE/SHARE. */
1331 deparseLockingClause(&context);
1332}
1333
1334/*
1335 * Construct a simple SELECT statement that retrieves desired columns
1336 * of the specified foreign table, and append it to "buf". The output
1337 * contains just "SELECT ... ".
1338 *
1339 * We also create an integer List of the columns being retrieved, which is
1340 * returned to *retrieved_attrs, unless we deparse the specified relation
1341 * as a subquery.
1342 *
1343 * tlist is the list of desired columns. is_subquery is the flag to
1344 * indicate whether to deparse the specified relation as a subquery.
1345 * Read prologue of deparseSelectStmtForRel() for details.
1346 */
1347static void
1348deparseSelectSql(List *tlist, bool is_subquery, List **retrieved_attrs,
1349 deparse_expr_cxt *context)
1350{
1351 StringInfo buf = context->buf;
1352 RelOptInfo *foreignrel = context->foreignrel;
1353 PlannerInfo *root = context->root;
1354 PgFdwRelationInfo *fpinfo = (PgFdwRelationInfo *) foreignrel->fdw_private;
1355
1356 /*
1357 * Construct SELECT list
1358 */
1359 appendStringInfoString(buf, "SELECT ");
1360
1361 if (is_subquery)
1362 {
1363 /*
1364 * For a relation that is deparsed as a subquery, emit expressions
1365 * specified in the relation's reltarget. Note that since this is for
1366 * the subquery, no need to care about *retrieved_attrs.
1367 */
1368 deparseSubqueryTargetList(context);
1369 }
1370 else if (IS_JOIN_REL(foreignrel) || IS_UPPER_REL(foreignrel))
1371 {
1372 /*
1373 * For a join or upper relation the input tlist gives the list of
1374 * columns required to be fetched from the foreign server.
1375 */
1376 deparseExplicitTargetList(tlist, false, retrieved_attrs, context);
1377 }
1378 else
1379 {
1380 /*
1381 * For a base relation fpinfo->attrs_used gives the list of columns
1382 * required to be fetched from the foreign server.
1383 */
1384 RangeTblEntry *rte = planner_rt_fetch(foreignrel->relid, root);
1385
1386 /*
1387 * Core code already has some lock on each rel being planned, so we
1388 * can use NoLock here.
1389 */
1390 Relation rel = table_open(rte->relid, NoLock);
1391
1392 deparseTargetList(buf, rte, foreignrel->relid, rel, false,
1393 fpinfo->attrs_used, false, retrieved_attrs);
1394 table_close(rel, NoLock);
1395 }
1396}
1397
1398/*
1399 * Construct a FROM clause and, if needed, a WHERE clause, and append those to
1400 * "buf".
1401 *
1402 * quals is the list of clauses to be included in the WHERE clause.
1403 * (These may or may not include RestrictInfo decoration.)
1404 */
1405static void
1406deparseFromExpr(List *quals, deparse_expr_cxt *context)
1407{
1408 StringInfo buf = context->buf;
1409 RelOptInfo *scanrel = context->scanrel;
1410 List *additional_conds = NIL;
1411
1412 /* For upper relations, scanrel must be either a joinrel or a baserel */
1413 Assert(!IS_UPPER_REL(context->foreignrel) ||
1414 IS_JOIN_REL(scanrel) || IS_SIMPLE_REL(scanrel));
1415
1416 /* Construct FROM clause */
1417 appendStringInfoString(buf, " FROM ");
1418 deparseFromExprForRel(buf, context->root, scanrel,
1419 (bms_membership(scanrel->relids) == BMS_MULTIPLE),
1420 (Index) 0, NULL, &additional_conds,
1421 context->params_list);
1422 appendWhereClause(quals, additional_conds, context);
1423 if (additional_conds != NIL)
1424 list_free_deep(additional_conds);
1425}
1426
1427/*
1428 * Emit a target list that retrieves the columns specified in attrs_used.
1429 * This is used for both SELECT and RETURNING targetlists; the is_returning
1430 * parameter is true only for a RETURNING targetlist.
1431 *
1432 * The tlist text is appended to buf, and we also create an integer List
1433 * of the columns being retrieved, which is returned to *retrieved_attrs.
1434 *
1435 * If qualify_col is true, add relation alias before the column name.
1436 */
1437static void
1438deparseTargetList(StringInfo buf,
1439 RangeTblEntry *rte,
1440 Index rtindex,
1441 Relation rel,
1442 bool is_returning,
1443 Bitmapset *attrs_used,
1444 bool qualify_col,
1445 List **retrieved_attrs)
1446{
1447 TupleDesc tupdesc = RelationGetDescr(rel);
1448 bool have_wholerow;
1449 bool first;
1450 int i;
1451
1452 *retrieved_attrs = NIL;
1453
1454 /* If there's a whole-row reference, we'll need all the columns. */
1455 have_wholerow = bms_is_member(0 - FirstLowInvalidHeapAttributeNumber,
1456 attrs_used);
1457
1458 first = true;
1459 for (i = 1; i <= tupdesc->natts; i++)
1460 {
1461 /* Ignore dropped attributes. */
1462 if (TupleDescCompactAttr(tupdesc, i - 1)->attisdropped)
1463 continue;
1464
1465 if (have_wholerow ||
1466 bms_is_member(i - FirstLowInvalidHeapAttributeNumber,
1467 attrs_used))
1468 {
1469 if (!first)
1470 appendStringInfoString(buf, ", ");
1471 else if (is_returning)
1472 appendStringInfoString(buf, " RETURNING ");
1473 first = false;
1474
1475 deparseColumnRef(buf, rtindex, i, rte, qualify_col);
1476
1477 *retrieved_attrs = lappend_int(*retrieved_attrs, i);
1478 }
1479 }
1480
1481 /*
1482 * Add ctid if needed. We currently don't support retrieving any other
1483 * system columns.
1484 */
1485 if (bms_is_member(SelfItemPointerAttributeNumber - FirstLowInvalidHeapAttributeNumber,
1486 attrs_used))
1487 {
1488 if (!first)
1489 appendStringInfoString(buf, ", ");
1490 else if (is_returning)
1491 appendStringInfoString(buf, " RETURNING ");
1492 first = false;
1493
1494 if (qualify_col)
1495 ADD_REL_QUALIFIER(buf, rtindex);
1496 appendStringInfoString(buf, "ctid");
1497
1498 *retrieved_attrs = lappend_int(*retrieved_attrs,
1499 SelfItemPointerAttributeNumber);
1500 }
1501
1502 /* Don't generate bad syntax if no undropped columns */
1503 if (first && !is_returning)
1504 appendStringInfoString(buf, "NULL");
1505}
1506
1507/*
1508 * Deparse the appropriate locking clause (FOR UPDATE or FOR SHARE) for a
1509 * given relation (context->scanrel).
1510 */
1511static void
1512deparseLockingClause(deparse_expr_cxt *context)
1513{
1514 StringInfo buf = context->buf;
1515 PlannerInfo *root = context->root;
1516 RelOptInfo *rel = context->scanrel;
1517 PgFdwRelationInfo *fpinfo = (PgFdwRelationInfo *) rel->fdw_private;
1518 int relid = -1;
1519
1520 while ((relid = bms_next_member(rel->relids, relid)) >= 0)
1521 {
1522 /*
1523 * Ignore relation if it appears in a lower subquery. Locking clause
1524 * for such a relation is included in the subquery if necessary.
1525 */
1526 if (bms_is_member(relid, fpinfo->lower_subquery_rels))
1527 continue;
1528
1529 /*
1530 * Add FOR UPDATE/SHARE if appropriate. We apply locking during the
1531 * initial row fetch, rather than later on as is done for local
1532 * tables. The extra roundtrips involved in trying to duplicate the
1533 * local semantics exactly don't seem worthwhile (see also comments
1534 * for RowMarkType).
1535 *
1536 * Note: because we actually run the query as a cursor, this assumes
1537 * that DECLARE CURSOR ... FOR UPDATE is supported, which it isn't
1538 * before 8.3.
1539 */
1540 if (bms_is_member(relid, root->all_result_relids) &&
1541 (root->parse->commandType == CMD_UPDATE ||
1542 root->parse->commandType == CMD_DELETE))
1543 {
1544 /* Relation is UPDATE/DELETE target, so use FOR UPDATE */
1545 appendStringInfoString(buf, " FOR UPDATE");
1546
1547 /* Add the relation alias if we are here for a join relation */
1548 if (IS_JOIN_REL(rel))
1549 appendStringInfo(buf, " OF %s%d", REL_ALIAS_PREFIX, relid);
1550 }
1551 else
1552 {
1553 PlanRowMark *rc = get_plan_rowmark(root->rowMarks, relid);
1554
1555 if (rc)
1556 {
1557 /*
1558 * Relation is specified as a FOR UPDATE/SHARE target, so
1559 * handle that. (But we could also see LCS_NONE, meaning this
1560 * isn't a target relation after all.)
1561 *
1562 * For now, just ignore any [NO] KEY specification, since (a)
1563 * it's not clear what that means for a remote table that we
1564 * don't have complete information about, and (b) it wouldn't
1565 * work anyway on older remote servers. Likewise, we don't
1566 * worry about NOWAIT.
1567 */
1568 switch (rc->strength)
1569 {
1570 case LCS_NONE:
1571 /* No locking needed */
1572 break;
1573 case LCS_FORKEYSHARE:
1574 case LCS_FORSHARE:
1575 appendStringInfoString(buf, " FOR SHARE");
1576 break;
1577 case LCS_FORNOKEYUPDATE:
1578 case LCS_FORUPDATE:
1579 appendStringInfoString(buf, " FOR UPDATE");
1580 break;
1581 }
1582
1583 /* Add the relation alias if we are here for a join relation */
1584 if (bms_membership(rel->relids) == BMS_MULTIPLE &&
1585 rc->strength != LCS_NONE)
1586 appendStringInfo(buf, " OF %s%d", REL_ALIAS_PREFIX, relid);
1587 }
1588 }
1589 }
1590}
1591
1592/*
1593 * Deparse conditions from the provided list and append them to buf.
1594 *
1595 * The conditions in the list are assumed to be ANDed. This function is used to
1596 * deparse WHERE clauses, JOIN .. ON clauses and HAVING clauses.
1597 *
1598 * Depending on the caller, the list elements might be either RestrictInfos
1599 * or bare clauses.
1600 */
1601static void
1602appendConditions(List *exprs, deparse_expr_cxt *context)
1603{
1604 int nestlevel;
1605 ListCell *lc;
1606 bool is_first = true;
1607 StringInfo buf = context->buf;
1608
1609 /* Make sure any constants in the exprs are printed portably */
1610 nestlevel = set_transmission_modes();
1611
1612 foreach(lc, exprs)
1613 {
1614 Expr *expr = (Expr *) lfirst(lc);
1615
1616 /* Extract clause from RestrictInfo, if required */
1617 if (IsA(expr, RestrictInfo))
1618 expr = ((RestrictInfo *) expr)->clause;
1619
1620 /* Connect expressions with "AND" and parenthesize each condition. */
1621 if (!is_first)
1622 appendStringInfoString(buf, " AND ");
1623
1624 appendStringInfoChar(buf, '(');
1625 deparseExpr(expr, context);
1626 appendStringInfoChar(buf, ')');
1627
1628 is_first = false;
1629 }
1630
1631 reset_transmission_modes(nestlevel);
1632}
1633
1634/*
1635 * Append WHERE clause, containing conditions from exprs and additional_conds,
1636 * to context->buf.
1637 */
1638static void
1639appendWhereClause(List *exprs, List *additional_conds, deparse_expr_cxt *context)
1640{
1641 StringInfo buf = context->buf;
1642 bool need_and = false;
1643 ListCell *lc;
1644
1645 if (exprs != NIL || additional_conds != NIL)
1646 appendStringInfoString(buf, " WHERE ");
1647
1648 /*
1649 * If there are some filters, append them.
1650 */
1651 if (exprs != NIL)
1652 {
1653 appendConditions(exprs, context);
1654 need_and = true;
1655 }
1656
1657 /*
1658 * If there are some EXISTS conditions, coming from SEMI-JOINS, append
1659 * them.
1660 */
1661 foreach(lc, additional_conds)
1662 {
1663 if (need_and)
1664 appendStringInfoString(buf, " AND ");
1665 appendStringInfoString(buf, (char *) lfirst(lc));
1666 need_and = true;
1667 }
1668}
1669
1670/* Output join name for given join type */
1671const char *
1672get_jointype_name(JoinType jointype)
1673{
1674 switch (jointype)
1675 {
1676 case JOIN_INNER:
1677 return "INNER";
1678
1679 case JOIN_LEFT:
1680 return "LEFT";
1681
1682 case JOIN_RIGHT:
1683 return "RIGHT";
1684
1685 case JOIN_FULL:
1686 return "FULL";
1687
1688 case JOIN_SEMI:
1689 return "SEMI";
1690
1691 default:
1692 /* Shouldn't come here, but protect from buggy code. */
1693 elog(ERROR, "unsupported join type %d", jointype);
1694 }
1695
1696 /* Keep compiler happy */
1697 return NULL;
1698}
1699
1700/*
1701 * Deparse given targetlist and append it to context->buf.
1702 *
1703 * tlist is list of TargetEntry's which in turn contain Var nodes.
1704 *
1705 * retrieved_attrs is the list of continuously increasing integers starting
1706 * from 1. It has same number of entries as tlist.
1707 *
1708 * This is used for both SELECT and RETURNING targetlists; the is_returning
1709 * parameter is true only for a RETURNING targetlist.
1710 */
1711static void
1712deparseExplicitTargetList(List *tlist,
1713 bool is_returning,
1714 List **retrieved_attrs,
1715 deparse_expr_cxt *context)
1716{
1717 ListCell *lc;
1718 StringInfo buf = context->buf;
1719 int i = 0;
1720
1721 *retrieved_attrs = NIL;
1722
1723 foreach(lc, tlist)
1724 {
1725 TargetEntry *tle = lfirst_node(TargetEntry, lc);
1726
1727 if (i > 0)
1728 appendStringInfoString(buf, ", ");
1729 else if (is_returning)
1730 appendStringInfoString(buf, " RETURNING ");
1731
1732 deparseExpr((Expr *) tle->expr, context);
1733
1734 *retrieved_attrs = lappend_int(*retrieved_attrs, i + 1);
1735 i++;
1736 }
1737
1738 if (i == 0 && !is_returning)
1739 appendStringInfoString(buf, "NULL");
1740}
1741
1742/*
1743 * Emit expressions specified in the given relation's reltarget.
1744 *
1745 * This is used for deparsing the given relation as a subquery.
1746 */
1747static void
1748deparseSubqueryTargetList(deparse_expr_cxt *context)
1749{
1750 StringInfo buf = context->buf;
1751 RelOptInfo *foreignrel = context->foreignrel;
1752 bool first;
1753 ListCell *lc;
1754
1755 /* Should only be called in these cases. */
1756 Assert(IS_SIMPLE_REL(foreignrel) || IS_JOIN_REL(foreignrel));
1757
1758 first = true;
1759 foreach(lc, foreignrel->reltarget->exprs)
1760 {
1761 Node *node = (Node *) lfirst(lc);
1762
1763 if (!first)
1764 appendStringInfoString(buf, ", ");
1765 first = false;
1766
1767 deparseExpr((Expr *) node, context);
1768 }
1769
1770 /* Don't generate bad syntax if no expressions */
1771 if (first)
1772 appendStringInfoString(buf, "NULL");
1773}
1774
1775/*
1776 * Construct FROM clause for given relation
1777 *
1778 * The function constructs ... JOIN ... ON ... for join relation. For a base
1779 * relation it just returns schema-qualified tablename, with the appropriate
1780 * alias if so requested.
1781 *
1782 * 'ignore_rel' is either zero or the RT index of a target relation. In the
1783 * latter case the function constructs FROM clause of UPDATE or USING clause
1784 * of DELETE; it deparses the join relation as if the relation never contained
1785 * the target relation, and creates a List of conditions to be deparsed into
1786 * the top-level WHERE clause, which is returned to *ignore_conds.
1787 *
1788 * 'additional_conds' is a pointer to a list of strings to be appended to
1789 * the WHERE clause, coming from lower-level SEMI-JOINs.
1790 */
1791static void
1792deparseFromExprForRel(StringInfo buf, PlannerInfo *root, RelOptInfo *foreignrel,
1793 bool use_alias, Index ignore_rel, List **ignore_conds,
1794 List **additional_conds, List **params_list)
1795{
1796 PgFdwRelationInfo *fpinfo = (PgFdwRelationInfo *) foreignrel->fdw_private;
1797
1798 if (IS_JOIN_REL(foreignrel))
1799 {
1800 StringInfoData join_sql_o;
1801 StringInfoData join_sql_i;
1802 RelOptInfo *outerrel = fpinfo->outerrel;
1803 RelOptInfo *innerrel = fpinfo->innerrel;
1804 bool outerrel_is_target = false;
1805 bool innerrel_is_target = false;
1806 List *additional_conds_i = NIL;
1807 List *additional_conds_o = NIL;
1808
1809 if (ignore_rel > 0 && bms_is_member(ignore_rel, foreignrel->relids))
1810 {
1811 /*
1812 * If this is an inner join, add joinclauses to *ignore_conds and
1813 * set it to empty so that those can be deparsed into the WHERE
1814 * clause. Note that since the target relation can never be
1815 * within the nullable side of an outer join, those could safely
1816 * be pulled up into the WHERE clause (see foreign_join_ok()).
1817 * Note also that since the target relation is only inner-joined
1818 * to any other relation in the query, all conditions in the join
1819 * tree mentioning the target relation could be deparsed into the
1820 * WHERE clause by doing this recursively.
1821 */
1822 if (fpinfo->jointype == JOIN_INNER)
1823 {
1824 *ignore_conds = list_concat(*ignore_conds,
1825 fpinfo->joinclauses);
1826 fpinfo->joinclauses = NIL;
1827 }
1828
1829 /*
1830 * Check if either of the input relations is the target relation.
1831 */
1832 if (outerrel->relid == ignore_rel)
1833 outerrel_is_target = true;
1834 else if (innerrel->relid == ignore_rel)
1835 innerrel_is_target = true;
1836 }
1837
1838 /* Deparse outer relation if not the target relation. */
1839 if (!outerrel_is_target)
1840 {
1841 initStringInfo(&join_sql_o);
1842 deparseRangeTblRef(&join_sql_o, root, outerrel,
1843 fpinfo->make_outerrel_subquery,
1844 ignore_rel, ignore_conds, &additional_conds_o,
1845 params_list);
1846
1847 /*
1848 * If inner relation is the target relation, skip deparsing it.
1849 * Note that since the join of the target relation with any other
1850 * relation in the query is an inner join and can never be within
1851 * the nullable side of an outer join, the join could be
1852 * interchanged with higher-level joins (cf. identity 1 on outer
1853 * join reordering shown in src/backend/optimizer/README), which
1854 * means it's safe to skip the target-relation deparsing here.
1855 */
1856 if (innerrel_is_target)
1857 {
1858 Assert(fpinfo->jointype == JOIN_INNER);
1859 Assert(fpinfo->joinclauses == NIL);
1860 appendBinaryStringInfo(buf, join_sql_o.data, join_sql_o.len);
1861 /* Pass EXISTS conditions to upper level */
1862 if (additional_conds_o != NIL)
1863 {
1864 Assert(*additional_conds == NIL);
1865 *additional_conds = additional_conds_o;
1866 }
1867 return;
1868 }
1869 }
1870
1871 /* Deparse inner relation if not the target relation. */
1872 if (!innerrel_is_target)
1873 {
1874 initStringInfo(&join_sql_i);
1875 deparseRangeTblRef(&join_sql_i, root, innerrel,
1876 fpinfo->make_innerrel_subquery,
1877 ignore_rel, ignore_conds, &additional_conds_i,
1878 params_list);
1879
1880 /*
1881 * SEMI-JOIN is deparsed as the EXISTS subquery. It references
1882 * outer and inner relations, so it should be evaluated as the
1883 * condition in the upper-level WHERE clause. We deparse the
1884 * condition and pass it to upper level callers as an
1885 * additional_conds list. Upper level callers are responsible for
1886 * inserting conditions from the list where appropriate.
1887 */
1888 if (fpinfo->jointype == JOIN_SEMI)
1889 {
1890 deparse_expr_cxt context;
1891 StringInfoData str;
1892
1893 /* Construct deparsed condition from this SEMI-JOIN */
1894 initStringInfo(&str);
1895 appendStringInfo(&str, "EXISTS (SELECT NULL FROM %s",
1896 join_sql_i.data);
1897
1898 context.buf = &str;
1899 context.foreignrel = foreignrel;
1900 context.scanrel = foreignrel;
1901 context.root = root;
1902 context.params_list = params_list;
1903
1904 /*
1905 * Append SEMI-JOIN clauses and EXISTS conditions from lower
1906 * levels to the current EXISTS subquery
1907 */
1908 appendWhereClause(fpinfo->joinclauses, additional_conds_i, &context);
1909
1910 /*
1911 * EXISTS conditions, coming from lower join levels, have just
1912 * been processed.
1913 */
1914 if (additional_conds_i != NIL)
1915 {
1916 list_free_deep(additional_conds_i);
1917 additional_conds_i = NIL;
1918 }
1919
1920 /* Close parentheses for EXISTS subquery */
1921 appendStringInfoChar(&str, ')');
1922
1923 *additional_conds = lappend(*additional_conds, str.data);
1924 }
1925
1926 /*
1927 * If outer relation is the target relation, skip deparsing it.
1928 * See the above note about safety.
1929 */
1930 if (outerrel_is_target)
1931 {
1932 Assert(fpinfo->jointype == JOIN_INNER);
1933 Assert(fpinfo->joinclauses == NIL);
1934 appendBinaryStringInfo(buf, join_sql_i.data, join_sql_i.len);
1935 /* Pass EXISTS conditions to the upper call */
1936 if (additional_conds_i != NIL)
1937 {
1938 Assert(*additional_conds == NIL);
1939 *additional_conds = additional_conds_i;
1940 }
1941 return;
1942 }
1943 }
1944
1945 /* Neither of the relations is the target relation. */
1946 Assert(!outerrel_is_target && !innerrel_is_target);
1947
1948 /*
1949 * For semijoin FROM clause is deparsed as an outer relation. An inner
1950 * relation and join clauses are converted to EXISTS condition and
1951 * passed to the upper level.
1952 */
1953 if (fpinfo->jointype == JOIN_SEMI)
1954 {
1955 appendBinaryStringInfo(buf, join_sql_o.data, join_sql_o.len);
1956 }
1957 else
1958 {
1959 /*
1960 * For a join relation FROM clause, entry is deparsed as
1961 *
1962 * ((outer relation) <join type> (inner relation) ON
1963 * (joinclauses))
1964 */
1965 appendStringInfo(buf, "(%s %s JOIN %s ON ", join_sql_o.data,
1966 get_jointype_name(fpinfo->jointype), join_sql_i.data);
1967
1968 /* Append join clause; (TRUE) if no join clause */
1969 if (fpinfo->joinclauses)
1970 {
1971 deparse_expr_cxt context;
1972
1973 context.buf = buf;
1974 context.foreignrel = foreignrel;
1975 context.scanrel = foreignrel;
1976 context.root = root;
1977 context.params_list = params_list;
1978
1979 appendStringInfoChar(buf, '(');
1980 appendConditions(fpinfo->joinclauses, &context);
1981 appendStringInfoChar(buf, ')');
1982 }
1983 else
1984 appendStringInfoString(buf, "(TRUE)");
1985
1986 /* End the FROM clause entry. */
1987 appendStringInfoChar(buf, ')');
1988 }
1989
1990 /*
1991 * Construct additional_conds to be passed to the upper caller from
1992 * current level additional_conds and additional_conds, coming from
1993 * inner and outer rels.
1994 */
1995 if (additional_conds_o != NIL)
1996 {
1997 *additional_conds = list_concat(*additional_conds,
1998 additional_conds_o);
1999 list_free(additional_conds_o);
2000 }
2001
2002 if (additional_conds_i != NIL)
2003 {
2004 *additional_conds = list_concat(*additional_conds,
2005 additional_conds_i);
2006 list_free(additional_conds_i);
2007 }
2008 }
2009 else
2010 {
2011 RangeTblEntry *rte = planner_rt_fetch(foreignrel->relid, root);
2012
2013 /*
2014 * Core code already has some lock on each rel being planned, so we
2015 * can use NoLock here.
2016 */
2017 Relation rel = table_open(rte->relid, NoLock);
2018
2019 deparseRelation(buf, rel);
2020
2021 /*
2022 * Add a unique alias to avoid any conflict in relation names due to
2023 * pulled up subqueries in the query being built for a pushed down
2024 * join.
2025 */
2026 if (use_alias)
2027 appendStringInfo(buf, " %s%d", REL_ALIAS_PREFIX, foreignrel->relid);
2028
2029 table_close(rel, NoLock);
2030 }
2031}
2032
2033/*
2034 * Append FROM clause entry for the given relation into buf.
2035 * Conditions from lower-level SEMI-JOINs are appended to additional_conds
2036 * and should be added to upper level WHERE clause.
2037 */
2038static void
2039deparseRangeTblRef(StringInfo buf, PlannerInfo *root, RelOptInfo *foreignrel,
2040 bool make_subquery, Index ignore_rel, List **ignore_conds,
2041 List **additional_conds, List **params_list)
2042{
2043 PgFdwRelationInfo *fpinfo = (PgFdwRelationInfo *) foreignrel->fdw_private;
2044
2045 /* Should only be called in these cases. */
2046 Assert(IS_SIMPLE_REL(foreignrel) || IS_JOIN_REL(foreignrel));
2047
2048 Assert(fpinfo->local_conds == NIL);
2049
2050 /* If make_subquery is true, deparse the relation as a subquery. */
2051 if (make_subquery)
2052 {
2053 List *retrieved_attrs;
2054 int ncols;
2055
2056 /*
2057 * The given relation shouldn't contain the target relation, because
2058 * this should only happen for input relations for a full join, and
2059 * such relations can never contain an UPDATE/DELETE target.
2060 */
2061 Assert(ignore_rel == 0 ||
2062 !bms_is_member(ignore_rel, foreignrel->relids));
2063
2064 /* Deparse the subquery representing the relation. */
2065 appendStringInfoChar(buf, '(');
2066 deparseSelectStmtForRel(buf, root, foreignrel, NIL,
2067 fpinfo->remote_conds, NIL,
2068 false, false, true,
2069 &retrieved_attrs, params_list);
2070 appendStringInfoChar(buf, ')');
2071
2072 /* Append the relation alias. */
2073 appendStringInfo(buf, " %s%d", SUBQUERY_REL_ALIAS_PREFIX,
2074 fpinfo->relation_index);
2075
2076 /*
2077 * Append the column aliases if needed. Note that the subquery emits
2078 * expressions specified in the relation's reltarget (see
2079 * deparseSubqueryTargetList).
2080 */
2081 ncols = list_length(foreignrel->reltarget->exprs);
2082 if (ncols > 0)
2083 {
2084 int i;
2085
2086 appendStringInfoChar(buf, '(');
2087 for (i = 1; i <= ncols; i++)
2088 {
2089 if (i > 1)
2090 appendStringInfoString(buf, ", ");
2091
2092 appendStringInfo(buf, "%s%d", SUBQUERY_COL_ALIAS_PREFIX, i);
2093 }
2094 appendStringInfoChar(buf, ')');
2095 }
2096 }
2097 else
2098 deparseFromExprForRel(buf, root, foreignrel, true, ignore_rel,
2099 ignore_conds, additional_conds,
2100 params_list);
2101}
2102
2103/*
2104 * deparse remote INSERT statement
2105 *
2106 * The statement text is appended to buf, and we also create an integer List
2107 * of the columns being retrieved by WITH CHECK OPTION or RETURNING (if any),
2108 * which is returned to *retrieved_attrs.
2109 *
2110 * This also stores end position of the VALUES clause, so that we can rebuild
2111 * an INSERT for a batch of rows later.
2112 */
2113void
2114deparseInsertSql(StringInfo buf, RangeTblEntry *rte,
2115 Index rtindex, Relation rel,
2116 List *targetAttrs, bool doNothing,
2117 List *withCheckOptionList, List *returningList,
2118 List **retrieved_attrs, int *values_end_len)
2119{
2120 TupleDesc tupdesc = RelationGetDescr(rel);
2121 AttrNumber pindex;
2122 bool first;
2123 ListCell *lc;
2124
2125 appendStringInfoString(buf, "INSERT INTO ");
2126 deparseRelation(buf, rel);
2127
2128 if (targetAttrs)
2129 {
2130 appendStringInfoChar(buf, '(');
2131
2132 first = true;
2133 foreach(lc, targetAttrs)
2134 {
2135 int attnum = lfirst_int(lc);
2136
2137 if (!first)
2138 appendStringInfoString(buf, ", ");
2139 first = false;
2140
2141 deparseColumnRef(buf, rtindex, attnum, rte, false);
2142 }
2143
2144 appendStringInfoString(buf, ") VALUES (");
2145
2146 pindex = 1;
2147 first = true;
2148 foreach(lc, targetAttrs)
2149 {
2150 int attnum = lfirst_int(lc);
2151 CompactAttribute *attr = TupleDescCompactAttr(tupdesc, attnum - 1);
2152
2153 if (!first)
2154 appendStringInfoString(buf, ", ");
2155 first = false;
2156
2157 if (attr->attgenerated)
2158 appendStringInfoString(buf, "DEFAULT");
2159 else
2160 {
2161 appendStringInfo(buf, "$%d", pindex);
2162 pindex++;
2163 }
2164 }
2165
2166 appendStringInfoChar(buf, ')');
2167 }
2168 else
2169 appendStringInfoString(buf, " DEFAULT VALUES");
2170 *values_end_len = buf->len;
2171
2172 if (doNothing)
2173 appendStringInfoString(buf, " ON CONFLICT DO NOTHING");
2174
2175 deparseReturningList(buf, rte, rtindex, rel,
2176 rel->trigdesc && rel->trigdesc->trig_insert_after_row,
2177 withCheckOptionList, returningList, retrieved_attrs);
2178}
2179
2180/*
2181 * rebuild remote INSERT statement
2182 *
2183 * Provided a number of rows in a batch, builds INSERT statement with the
2184 * right number of parameters.
2185 */
2186void
2187rebuildInsertSql(StringInfo buf, Relation rel,
2188 char *orig_query, List *target_attrs,
2189 int values_end_len, int num_params,
2190 int num_rows)
2191{
2192 TupleDesc tupdesc = RelationGetDescr(rel);
2193 int i;
2194 int pindex;
2195 bool first;
2196 ListCell *lc;
2197
2198 /* Make sure the values_end_len is sensible */
2199 Assert((values_end_len > 0) && (values_end_len <= strlen(orig_query)));
2200
2201 /* Copy up to the end of the first record from the original query */
2202 appendBinaryStringInfo(buf, orig_query, values_end_len);
2203
2204 /*
2205 * Add records to VALUES clause (we already have parameters for the first
2206 * row, so start at the right offset).
2207 */
2208 pindex = num_params + 1;
2209 for (i = 0; i < num_rows; i++)
2210 {
2211 appendStringInfoString(buf, ", (");
2212
2213 first = true;
2214 foreach(lc, target_attrs)
2215 {
2216 int attnum = lfirst_int(lc);
2217 CompactAttribute *attr = TupleDescCompactAttr(tupdesc, attnum - 1);
2218
2219 if (!first)
2220 appendStringInfoString(buf, ", ");
2221 first = false;
2222
2223 if (attr->attgenerated)
2224 appendStringInfoString(buf, "DEFAULT");
2225 else
2226 {
2227 appendStringInfo(buf, "$%d", pindex);
2228 pindex++;
2229 }
2230 }
2231
2232 appendStringInfoChar(buf, ')');
2233 }
2234
2235 /* Copy stuff after VALUES clause from the original query */
2236 appendStringInfoString(buf, orig_query + values_end_len);
2237}
2238
2239/*
2240 * deparse remote UPDATE statement
2241 *
2242 * The statement text is appended to buf, and we also create an integer List
2243 * of the columns being retrieved by WITH CHECK OPTION or RETURNING (if any),
2244 * which is returned to *retrieved_attrs.
2245 */
2246void
2247deparseUpdateSql(StringInfo buf, RangeTblEntry *rte,
2248 Index rtindex, Relation rel,
2249 List *targetAttrs,
2250 List *withCheckOptionList, List *returningList,
2251 List **retrieved_attrs)
2252{
2253 TupleDesc tupdesc = RelationGetDescr(rel);
2254 AttrNumber pindex;
2255 bool first;
2256 ListCell *lc;
2257
2258 appendStringInfoString(buf, "UPDATE ");
2259 deparseRelation(buf, rel);
2260 appendStringInfoString(buf, " SET ");
2261
2262 pindex = 2; /* ctid is always the first param */
2263 first = true;
2264 foreach(lc, targetAttrs)
2265 {
2266 int attnum = lfirst_int(lc);
2267 CompactAttribute *attr = TupleDescCompactAttr(tupdesc, attnum - 1);
2268
2269 if (!first)
2270 appendStringInfoString(buf, ", ");
2271 first = false;
2272
2273 deparseColumnRef(buf, rtindex, attnum, rte, false);
2274 if (attr->attgenerated)
2275 appendStringInfoString(buf, " = DEFAULT");
2276 else
2277 {
2278 appendStringInfo(buf, " = $%d", pindex);
2279 pindex++;
2280 }
2281 }
2282 appendStringInfoString(buf, " WHERE ctid = $1");
2283
2284 deparseReturningList(buf, rte, rtindex, rel,
2285 rel->trigdesc && rel->trigdesc->trig_update_after_row,
2286 withCheckOptionList, returningList, retrieved_attrs);
2287}
2288
2289/*
2290 * deparse remote UPDATE statement
2291 *
2292 * 'buf' is the output buffer to append the statement to
2293 * 'rtindex' is the RT index of the associated target relation
2294 * 'rel' is the relation descriptor for the target relation
2295 * 'foreignrel' is the RelOptInfo for the target relation or the join relation
2296 * containing all base relations in the query
2297 * 'targetlist' is the tlist of the underlying foreign-scan plan node
2298 * (note that this only contains new-value expressions and junk attrs)
2299 * 'targetAttrs' is the target columns of the UPDATE
2300 * 'remote_conds' is the qual clauses that must be evaluated remotely
2301 * '*params_list' is an output list of exprs that will become remote Params
2302 * 'returningList' is the RETURNING targetlist
2303 * '*retrieved_attrs' is an output list of integers of columns being retrieved
2304 * by RETURNING (if any)
2305 */
2306void
2307deparseDirectUpdateSql(StringInfo buf, PlannerInfo *root,
2308 Index rtindex, Relation rel,
2309 RelOptInfo *foreignrel,
2310 List *targetlist,
2311 List *targetAttrs,
2312 List *remote_conds,
2313 List **params_list,
2314 List *returningList,
2315 List **retrieved_attrs)
2316{
2317 deparse_expr_cxt context;
2318 int nestlevel;
2319 bool first;
2320 RangeTblEntry *rte = planner_rt_fetch(rtindex, root);
2321 ListCell *lc,
2322 *lc2;
2323 List *additional_conds = NIL;
2324
2325 /* Set up context struct for recursion */
2326 context.root = root;
2327 context.foreignrel = foreignrel;
2328 context.scanrel = foreignrel;
2329 context.buf = buf;
2330 context.params_list = params_list;
2331
2332 appendStringInfoString(buf, "UPDATE ");
2333 deparseRelation(buf, rel);
2334 if (foreignrel->reloptkind == RELOPT_JOINREL)
2335 appendStringInfo(buf, " %s%d", REL_ALIAS_PREFIX, rtindex);
2336 appendStringInfoString(buf, " SET ");
2337
2338 /* Make sure any constants in the exprs are printed portably */
2339 nestlevel = set_transmission_modes();
2340
2341 first = true;
2342 forboth(lc, targetlist, lc2, targetAttrs)
2343 {
2344 TargetEntry *tle = lfirst_node(TargetEntry, lc);
2345 int attnum = lfirst_int(lc2);
2346
2347 /* update's new-value expressions shouldn't be resjunk */
2348 Assert(!tle->resjunk);
2349
2350 if (!first)
2351 appendStringInfoString(buf, ", ");
2352 first = false;
2353
2354 deparseColumnRef(buf, rtindex, attnum, rte, false);
2355 appendStringInfoString(buf, " = ");
2356 deparseExpr((Expr *) tle->expr, &context);
2357 }
2358
2359 reset_transmission_modes(nestlevel);
2360
2361 if (foreignrel->reloptkind == RELOPT_JOINREL)
2362 {
2363 List *ignore_conds = NIL;
2364
2365
2366 appendStringInfoString(buf, " FROM ");
2367 deparseFromExprForRel(buf, root, foreignrel, true, rtindex,
2368 &ignore_conds, &additional_conds, params_list);
2369 remote_conds = list_concat(remote_conds, ignore_conds);
2370 }
2371
2372 appendWhereClause(remote_conds, additional_conds, &context);
2373
2374 if (additional_conds != NIL)
2375 list_free_deep(additional_conds);
2376
2377 if (foreignrel->reloptkind == RELOPT_JOINREL)
2378 deparseExplicitTargetList(returningList, true, retrieved_attrs,
2379 &context);
2380 else
2381 deparseReturningList(buf, rte, rtindex, rel, false,
2382 NIL, returningList, retrieved_attrs);
2383}
2384
2385/*
2386 * deparse remote DELETE statement
2387 *
2388 * The statement text is appended to buf, and we also create an integer List
2389 * of the columns being retrieved by RETURNING (if any), which is returned
2390 * to *retrieved_attrs.
2391 */
2392void
2393deparseDeleteSql(StringInfo buf, RangeTblEntry *rte,
2394 Index rtindex, Relation rel,
2395 List *returningList,
2396 List **retrieved_attrs)
2397{
2398 appendStringInfoString(buf, "DELETE FROM ");
2399 deparseRelation(buf, rel);
2400 appendStringInfoString(buf, " WHERE ctid = $1");
2401
2402 deparseReturningList(buf, rte, rtindex, rel,
2403 rel->trigdesc && rel->trigdesc->trig_delete_after_row,
2404 NIL, returningList, retrieved_attrs);
2405}
2406
2407/*
2408 * deparse remote DELETE statement
2409 *
2410 * 'buf' is the output buffer to append the statement to
2411 * 'rtindex' is the RT index of the associated target relation
2412 * 'rel' is the relation descriptor for the target relation
2413 * 'foreignrel' is the RelOptInfo for the target relation or the join relation
2414 * containing all base relations in the query
2415 * 'remote_conds' is the qual clauses that must be evaluated remotely
2416 * '*params_list' is an output list of exprs that will become remote Params
2417 * 'returningList' is the RETURNING targetlist
2418 * '*retrieved_attrs' is an output list of integers of columns being retrieved
2419 * by RETURNING (if any)
2420 */
2421void
2422deparseDirectDeleteSql(StringInfo buf, PlannerInfo *root,
2423 Index rtindex, Relation rel,
2424 RelOptInfo *foreignrel,
2425 List *remote_conds,
2426 List **params_list,
2427 List *returningList,
2428 List **retrieved_attrs)
2429{
2430 deparse_expr_cxt context;
2431 List *additional_conds = NIL;
2432
2433 /* Set up context struct for recursion */
2434 context.root = root;
2435 context.foreignrel = foreignrel;
2436 context.scanrel = foreignrel;
2437 context.buf = buf;
2438 context.params_list = params_list;
2439
2440 appendStringInfoString(buf, "DELETE FROM ");
2441 deparseRelation(buf, rel);
2442 if (foreignrel->reloptkind == RELOPT_JOINREL)
2443 appendStringInfo(buf, " %s%d", REL_ALIAS_PREFIX, rtindex);
2444
2445 if (foreignrel->reloptkind == RELOPT_JOINREL)
2446 {
2447 List *ignore_conds = NIL;
2448
2449 appendStringInfoString(buf, " USING ");
2450 deparseFromExprForRel(buf, root, foreignrel, true, rtindex,
2451 &ignore_conds, &additional_conds, params_list);
2452 remote_conds = list_concat(remote_conds, ignore_conds);
2453 }
2454
2455 appendWhereClause(remote_conds, additional_conds, &context);
2456
2457 if (additional_conds != NIL)
2458 list_free_deep(additional_conds);
2459
2460 if (foreignrel->reloptkind == RELOPT_JOINREL)
2461 deparseExplicitTargetList(returningList, true, retrieved_attrs,
2462 &context);
2463 else
2464 deparseReturningList(buf, planner_rt_fetch(rtindex, root),
2465 rtindex, rel, false,
2466 NIL, returningList, retrieved_attrs);
2467}
2468
2469/*
2470 * Add a RETURNING clause, if needed, to an INSERT/UPDATE/DELETE.
2471 */
2472static void
2473deparseReturningList(StringInfo buf, RangeTblEntry *rte,
2474 Index rtindex, Relation rel,
2475 bool trig_after_row,
2476 List *withCheckOptionList,
2477 List *returningList,
2478 List **retrieved_attrs)
2479{
2480 Bitmapset *attrs_used = NULL;
2481
2482 if (trig_after_row)
2483 {
2484 /* whole-row reference acquires all non-system columns */
2485 attrs_used =
2486 bms_make_singleton(0 - FirstLowInvalidHeapAttributeNumber);
2487 }
2488
2489 if (withCheckOptionList != NIL)
2490 {
2491 /*
2492 * We need the attrs, non-system and system, mentioned in the local
2493 * query's WITH CHECK OPTION list.
2494 *
2495 * Note: we do this to ensure that WCO constraints will be evaluated
2496 * on the data actually inserted/updated on the remote side, which
2497 * might differ from the data supplied by the core code, for example
2498 * as a result of remote triggers.
2499 */
2500 pull_varattnos((Node *) withCheckOptionList, rtindex,
2501 &attrs_used);
2502 }
2503
2504 if (returningList != NIL)
2505 {
2506 /*
2507 * We need the attrs, non-system and system, mentioned in the local
2508 * query's RETURNING list.
2509 */
2510 pull_varattnos((Node *) returningList, rtindex,
2511 &attrs_used);
2512 }
2513
2514 if (attrs_used != NULL)
2515 deparseTargetList(buf, rte, rtindex, rel, true, attrs_used, false,
2516 retrieved_attrs);
2517 else
2518 *retrieved_attrs = NIL;
2519}
2520
2521/*
2522 * Construct SELECT statement to acquire size in blocks of given relation.
2523 *
2524 * Note: we use local definition of block size, not remote definition.
2525 * This is perhaps debatable.
2526 *
2527 * Note: pg_relation_size() exists in 8.1 and later.
2528 */
2529void
2530deparseAnalyzeSizeSql(StringInfo buf, Relation rel)
2531{
2532 StringInfoData relname;
2533
2534 /* We'll need the remote relation name as a literal. */
2535 initStringInfo(&relname);
2536 deparseRelation(&relname, rel);
2537
2538 appendStringInfoString(buf, "SELECT pg_catalog.pg_relation_size(");
2539 deparseStringLiteral(buf, relname.data);
2540 appendStringInfo(buf, "::pg_catalog.regclass) / %d", BLCKSZ);
2541}
2542
2543/*
2544 * Construct SELECT statement to acquire the number of rows and the relkind of
2545 * a relation.
2546 *
2547 * Note: we just return the remote server's reltuples value, which might
2548 * be off a good deal, but it doesn't seem worth working harder. See
2549 * comments in postgresAcquireSampleRowsFunc.
2550 */
2551void
2552deparseAnalyzeInfoSql(StringInfo buf, Relation rel)
2553{
2554 StringInfoData relname;
2555
2556 /* We'll need the remote relation name as a literal. */
2557 initStringInfo(&relname);
2558 deparseRelation(&relname, rel);
2559
2560 appendStringInfoString(buf, "SELECT reltuples, relkind FROM pg_catalog.pg_class WHERE oid = ");
2561 deparseStringLiteral(buf, relname.data);
2562 appendStringInfoString(buf, "::pg_catalog.regclass");
2563}
2564
2565/*
2566 * Construct SELECT statement to acquire sample rows of given relation.
2567 *
2568 * SELECT command is appended to buf, and list of columns retrieved
2569 * is returned to *retrieved_attrs.
2570 *
2571 * We only support sampling methods we can decide based on server version.
2572 * Allowing custom TSM modules (like tsm_system_rows) might be useful, but it
2573 * would require detecting which extensions are installed, to allow automatic
2574 * fall-back. Moreover, the methods may use different parameters like number
2575 * of rows (and not sampling rate). So we leave this for future improvements.
2576 *
2577 * Using random() to sample rows on the remote server has the advantage that
2578 * this works on all PostgreSQL versions (unlike TABLESAMPLE), and that it
2579 * does the sampling on the remote side (without transferring everything and
2580 * then discarding most rows).
2581 *
2582 * The disadvantage is that we still have to read all rows and evaluate the
2583 * random(), while TABLESAMPLE (at least with the "system" method) may skip.
2584 * It's not that different from the "bernoulli" method, though.
2585 *
2586 * We could also do "ORDER BY random() LIMIT x", which would always pick
2587 * the expected number of rows, but it requires sorting so it may be much
2588 * more expensive (particularly on large tables, which is what the
2589 * remote sampling is meant to improve).
2590 */
2591void
2592deparseAnalyzeSql(StringInfo buf, Relation rel,
2593 PgFdwSamplingMethod sample_method, double sample_frac,
2594 List **retrieved_attrs)
2595{
2596 Oid relid = RelationGetRelid(rel);
2597 TupleDesc tupdesc = RelationGetDescr(rel);
2598 int i;
2599 char *colname;
2600 List *options;
2601 ListCell *lc;
2602 bool first = true;
2603
2604 *retrieved_attrs = NIL;
2605
2606 appendStringInfoString(buf, "SELECT ");
2607 for (i = 0; i < tupdesc->natts; i++)
2608 {
2609 /* Ignore dropped columns. */
2610 if (TupleDescAttr(tupdesc, i)->attisdropped)
2611 continue;
2612
2613 if (!first)
2614 appendStringInfoString(buf, ", ");
2615 first = false;
2616
2617 /* Use attribute name or column_name option. */
2618 colname = NameStr(TupleDescAttr(tupdesc, i)->attname);
2619 options = GetForeignColumnOptions(relid, i + 1);
2620
2621 foreach(lc, options)
2622 {
2623 DefElem *def = (DefElem *) lfirst(lc);
2624
2625 if (strcmp(def->defname, "column_name") == 0)
2626 {
2627 colname = defGetString(def);
2628 break;
2629 }
2630 }
2631
2632 appendStringInfoString(buf, quote_identifier(colname));
2633
2634 *retrieved_attrs = lappend_int(*retrieved_attrs, i + 1);
2635 }
2636
2637 /* Don't generate bad syntax for zero-column relation. */
2638 if (first)
2639 appendStringInfoString(buf, "NULL");
2640
2641 /*
2642 * Construct FROM clause, and perhaps WHERE clause too, depending on the
2643 * selected sampling method.
2644 */
2645 appendStringInfoString(buf, " FROM ");
2646 deparseRelation(buf, rel);
2647
2648 switch (sample_method)
2649 {
2650 case ANALYZE_SAMPLE_OFF:
2651 /* nothing to do here */
2652 break;
2653
2654 case ANALYZE_SAMPLE_RANDOM:
2655 appendStringInfo(buf, " WHERE pg_catalog.random() < %f", sample_frac);
2656 break;
2657
2658 case ANALYZE_SAMPLE_SYSTEM:
2659 appendStringInfo(buf, " TABLESAMPLE SYSTEM(%f)", (100.0 * sample_frac));
2660 break;
2661
2662 case ANALYZE_SAMPLE_BERNOULLI:
2663 appendStringInfo(buf, " TABLESAMPLE BERNOULLI(%f)", (100.0 * sample_frac));
2664 break;
2665
2666 case ANALYZE_SAMPLE_AUTO:
2667 /* should have been resolved into actual method */
2668 elog(ERROR, "unexpected sampling method");
2669 break;
2670 }
2671}
2672
2673/*
2674 * Construct a simple "TRUNCATE rel" statement
2675 */
2676void
2677deparseTruncateSql(StringInfo buf,
2678 List *rels,
2679 DropBehavior behavior,
2680 bool restart_seqs)
2681{
2682 ListCell *cell;
2683
2684 appendStringInfoString(buf, "TRUNCATE ");
2685
2686 foreach(cell, rels)
2687 {
2688 Relation rel = lfirst(cell);
2689
2690 if (cell != list_head(rels))
2691 appendStringInfoString(buf, ", ");
2692
2693 deparseRelation(buf, rel);
2694 }
2695
2696 appendStringInfo(buf, " %s IDENTITY",
2697 restart_seqs ? "RESTART" : "CONTINUE");
2698
2699 if (behavior == DROP_RESTRICT)
2700 appendStringInfoString(buf, " RESTRICT");
2701 else if (behavior == DROP_CASCADE)
2702 appendStringInfoString(buf, " CASCADE");
2703}
2704
2705/*
2706 * Construct name to use for given column, and emit it into buf.
2707 * If it has a column_name FDW option, use that instead of attribute name.
2708 *
2709 * If qualify_col is true, qualify column name with the alias of relation.
2710 */
2711static void
2712deparseColumnRef(StringInfo buf, int varno, int varattno, RangeTblEntry *rte,
2713 bool qualify_col)
2714{
2715 /* We support fetching the remote side's CTID and OID. */
2716 if (varattno == SelfItemPointerAttributeNumber)
2717 {
2718 if (qualify_col)
2719 ADD_REL_QUALIFIER(buf, varno);
2720 appendStringInfoString(buf, "ctid");
2721 }
2722 else if (varattno < 0)
2723 {
2724 /*
2725 * All other system attributes are fetched as 0, except for table OID,
2726 * which is fetched as the local table OID. However, we must be
2727 * careful; the table could be beneath an outer join, in which case it
2728 * must go to NULL whenever the rest of the row does.
2729 */
2730 Oid fetchval = 0;
2731
2732 if (varattno == TableOidAttributeNumber)
2733 fetchval = rte->relid;
2734
2735 if (qualify_col)
2736 {
2737 appendStringInfoString(buf, "CASE WHEN (");
2738 ADD_REL_QUALIFIER(buf, varno);
2739 appendStringInfo(buf, "*)::text IS NOT NULL THEN %u END", fetchval);
2740 }
2741 else
2742 appendStringInfo(buf, "%u", fetchval);
2743 }
2744 else if (varattno == 0)
2745 {
2746 /* Whole row reference */
2747 Relation rel;
2748 Bitmapset *attrs_used;
2749
2750 /* Required only to be passed down to deparseTargetList(). */
2751 List *retrieved_attrs;
2752
2753 /*
2754 * The lock on the relation will be held by upper callers, so it's
2755 * fine to open it with no lock here.
2756 */
2757 rel = table_open(rte->relid, NoLock);
2758
2759 /*
2760 * The local name of the foreign table can not be recognized by the
2761 * foreign server and the table it references on foreign server might
2762 * have different column ordering or different columns than those
2763 * declared locally. Hence we have to deparse whole-row reference as
2764 * ROW(columns referenced locally). Construct this by deparsing a
2765 * "whole row" attribute.
2766 */
2767 attrs_used = bms_add_member(NULL,
2768 0 - FirstLowInvalidHeapAttributeNumber);
2769
2770 /*
2771 * In case the whole-row reference is under an outer join then it has
2772 * to go NULL whenever the rest of the row goes NULL. Deparsing a join
2773 * query would always involve multiple relations, thus qualify_col
2774 * would be true.
2775 */
2776 if (qualify_col)
2777 {
2778 appendStringInfoString(buf, "CASE WHEN (");
2779 ADD_REL_QUALIFIER(buf, varno);
2780 appendStringInfoString(buf, "*)::text IS NOT NULL THEN ");
2781 }
2782
2783 appendStringInfoString(buf, "ROW(");
2784 deparseTargetList(buf, rte, varno, rel, false, attrs_used, qualify_col,
2785 &retrieved_attrs);
2786 appendStringInfoChar(buf, ')');
2787
2788 /* Complete the CASE WHEN statement started above. */
2789 if (qualify_col)
2790 appendStringInfoString(buf, " END");
2791
2792 table_close(rel, NoLock);
2793 bms_free(attrs_used);
2794 }
2795 else
2796 {
2797 char *colname = NULL;
2798 List *options;
2799 ListCell *lc;
2800
2801 /* varno must not be any of OUTER_VAR, INNER_VAR and INDEX_VAR. */
2802 Assert(!IS_SPECIAL_VARNO(varno));
2803
2804 /*
2805 * If it's a column of a foreign table, and it has the column_name FDW
2806 * option, use that value.
2807 */
2808 options = GetForeignColumnOptions(rte->relid, varattno);
2809 foreach(lc, options)
2810 {
2811 DefElem *def = (DefElem *) lfirst(lc);
2812
2813 if (strcmp(def->defname, "column_name") == 0)
2814 {
2815 colname = defGetString(def);
2816 break;
2817 }
2818 }
2819
2820 /*
2821 * If it's a column of a regular table or it doesn't have column_name
2822 * FDW option, use attribute name.
2823 */
2824 if (colname == NULL)
2825 colname = get_attname(rte->relid, varattno, false);
2826
2827 if (qualify_col)
2828 ADD_REL_QUALIFIER(buf, varno);
2829
2830 appendStringInfoString(buf, quote_identifier(colname));
2831 }
2832}
2833
2834/*
2835 * Append remote name of specified foreign table to buf.
2836 * Use value of table_name FDW option (if any) instead of relation's name.
2837 * Similarly, schema_name FDW option overrides schema name.
2838 */
2839static void
2840deparseRelation(StringInfo buf, Relation rel)
2841{
2842 ForeignTable *table;
2843 const char *nspname = NULL;
2844 const char *relname = NULL;
2845 ListCell *lc;
2846
2847 /* obtain additional catalog information. */
2848 table = GetForeignTable(RelationGetRelid(rel));
2849
2850 /*
2851 * Use value of FDW options if any, instead of the name of object itself.
2852 */
2853 foreach(lc, table->options)
2854 {
2855 DefElem *def = (DefElem *) lfirst(lc);
2856
2857 if (strcmp(def->defname, "schema_name") == 0)
2858 nspname = defGetString(def);
2859 else if (strcmp(def->defname, "table_name") == 0)
2860 relname = defGetString(def);
2861 }
2862
2863 /*
2864 * Note: we could skip printing the schema name if it's pg_catalog, but
2865 * that doesn't seem worth the trouble.
2866 */
2867 if (nspname == NULL)
2868 nspname = get_namespace_name(RelationGetNamespace(rel));
2869 if (relname == NULL)
2870 relname = RelationGetRelationName(rel);
2871
2872 appendStringInfo(buf, "%s.%s",
2873 quote_identifier(nspname), quote_identifier(relname));
2874}
2875
2876/*
2877 * Append a SQL string literal representing "val" to buf.
2878 */
2879void
2880deparseStringLiteral(StringInfo buf, const char *val)
2881{
2882 const char *valptr;
2883
2884 /*
2885 * Rather than making assumptions about the remote server's value of
2886 * standard_conforming_strings, always use E'foo' syntax if there are any
2887 * backslashes. This will fail on remote servers before 8.1, but those
2888 * are long out of support.
2889 */
2890 if (strchr(val, '\\') != NULL)
2891 appendStringInfoChar(buf, ESCAPE_STRING_SYNTAX);
2892 appendStringInfoChar(buf, '\'');
2893 for (valptr = val; *valptr; valptr++)
2894 {
2895 char ch = *valptr;
2896
2897 if (SQL_STR_DOUBLE(ch, true))
2898 appendStringInfoChar(buf, ch);
2899 appendStringInfoChar(buf, ch);
2900 }
2901 appendStringInfoChar(buf, '\'');
2902}
2903
2904/*
2905 * Deparse given expression into context->buf.
2906 *
2907 * This function must support all the same node types that foreign_expr_walker
2908 * accepts.
2909 *
2910 * Note: unlike ruleutils.c, we just use a simple hard-wired parenthesization
2911 * scheme: anything more complex than a Var, Const, function call or cast
2912 * should be self-parenthesized.
2913 */
2914static void
2915deparseExpr(Expr *node, deparse_expr_cxt *context)
2916{
2917 if (node == NULL)
2918 return;
2919
2920 switch (nodeTag(node))
2921 {
2922 case T_Var:
2923 deparseVar((Var *) node, context);
2924 break;
2925 case T_Const:
2926 deparseConst((Const *) node, context, 0);
2927 break;
2928 case T_Param:
2929 deparseParam((Param *) node, context);
2930 break;
2931 case T_SubscriptingRef:
2932 deparseSubscriptingRef((SubscriptingRef *) node, context);
2933 break;
2934 case T_FuncExpr:
2935 deparseFuncExpr((FuncExpr *) node, context);
2936 break;
2937 case T_OpExpr:
2938 deparseOpExpr((OpExpr *) node, context);
2939 break;
2940 case T_DistinctExpr:
2941 deparseDistinctExpr((DistinctExpr *) node, context);
2942 break;
2943 case T_ScalarArrayOpExpr:
2944 deparseScalarArrayOpExpr((ScalarArrayOpExpr *) node, context);
2945 break;
2946 case T_RelabelType:
2947 deparseRelabelType((RelabelType *) node, context);
2948 break;
2949 case T_ArrayCoerceExpr:
2950 deparseArrayCoerceExpr((ArrayCoerceExpr *) node, context);
2951 break;
2952 case T_BoolExpr:
2953 deparseBoolExpr((BoolExpr *) node, context);
2954 break;
2955 case T_NullTest:
2956 deparseNullTest((NullTest *) node, context);
2957 break;
2958 case T_CaseExpr:
2959 deparseCaseExpr((CaseExpr *) node, context);
2960 break;
2961 case T_ArrayExpr:
2962 deparseArrayExpr((ArrayExpr *) node, context);
2963 break;
2964 case T_Aggref:
2965 deparseAggref((Aggref *) node, context);
2966 break;
2967 default:
2968 elog(ERROR, "unsupported expression type for deparse: %d",
2969 (int) nodeTag(node));
2970 break;
2971 }
2972}
2973
2974/*
2975 * Deparse given Var node into context->buf.
2976 *
2977 * If the Var belongs to the foreign relation, just print its remote name.
2978 * Otherwise, it's effectively a Param (and will in fact be a Param at
2979 * run time). Handle it the same way we handle plain Params --- see
2980 * deparseParam for comments.
2981 */
2982static void
2983deparseVar(Var *node, deparse_expr_cxt *context)
2984{
2985 Relids relids = context->scanrel->relids;
2986 int relno;
2987 int colno;
2988
2989 /* Qualify columns when multiple relations are involved. */
2990 bool qualify_col = (bms_membership(relids) == BMS_MULTIPLE);
2991
2992 /*
2993 * If the Var belongs to the foreign relation that is deparsed as a
2994 * subquery, use the relation and column alias to the Var provided by the
2995 * subquery, instead of the remote name.
2996 */
2997 if (is_subquery_var(node, context->scanrel, &relno, &colno))
2998 {
2999 appendStringInfo(context->buf, "%s%d.%s%d",
3000 SUBQUERY_REL_ALIAS_PREFIX, relno,
3001 SUBQUERY_COL_ALIAS_PREFIX, colno);
3002 return;
3003 }
3004
3005 if (bms_is_member(node->varno, relids) && node->varlevelsup == 0)
3006 deparseColumnRef(context->buf, node->varno, node->varattno,
3007 planner_rt_fetch(node->varno, context->root),
3008 qualify_col);
3009 else
3010 {
3011 /* Treat like a Param */
3012 if (context->params_list)
3013 {
3014 int pindex = 0;
3015 ListCell *lc;
3016
3017 /* find its index in params_list */
3018 foreach(lc, *context->params_list)
3019 {
3020 pindex++;
3021 if (equal(node, (Node *) lfirst(lc)))
3022 break;
3023 }
3024 if (lc == NULL)
3025 {
3026 /* not in list, so add it */
3027 pindex++;
3028 *context->params_list = lappend(*context->params_list, node);
3029 }
3030
3031 printRemoteParam(pindex, node->vartype, node->vartypmod, context);
3032 }
3033 else
3034 {
3035 printRemotePlaceholder(node->vartype, node->vartypmod, context);
3036 }
3037 }
3038}
3039
3040/*
3041 * Deparse given constant value into context->buf.
3042 *
3043 * This function has to be kept in sync with ruleutils.c's get_const_expr.
3044 *
3045 * As in that function, showtype can be -1 to never show "::typename"
3046 * decoration, +1 to always show it, or 0 to show it only if the constant
3047 * wouldn't be assumed to be the right type by default.
3048 *
3049 * In addition, this code allows showtype to be -2 to indicate that we should
3050 * not show "::typename" decoration if the constant is printed as an untyped
3051 * literal or NULL (while in other cases, behaving as for showtype == 0).
3052 */
3053static void
3054deparseConst(Const *node, deparse_expr_cxt *context, int showtype)
3055{
3056 StringInfo buf = context->buf;
3057 Oid typoutput;
3058 bool typIsVarlena;
3059 char *extval;
3060 bool isfloat = false;
3061 bool isstring = false;
3062 bool needlabel;
3063
3064 if (node->constisnull)
3065 {
3066 appendStringInfoString(buf, "NULL");
3067 if (showtype >= 0)
3068 appendStringInfo(buf, "::%s",
3069 deparse_type_name(node->consttype,
3070 node->consttypmod));
3071 return;
3072 }
3073
3074 getTypeOutputInfo(node->consttype,
3075 &typoutput, &typIsVarlena);
3076 extval = OidOutputFunctionCall(typoutput, node->constvalue);
3077
3078 switch (node->consttype)
3079 {
3080 case INT2OID:
3081 case INT4OID:
3082 case INT8OID:
3083 case OIDOID:
3084 case FLOAT4OID:
3085 case FLOAT8OID:
3086 case NUMERICOID:
3087 {
3088 /*
3089 * No need to quote unless it's a special value such as 'NaN'.
3090 * See comments in get_const_expr().
3091 */
3092 if (strspn(extval, "0123456789+-eE.") == strlen(extval))
3093 {
3094 if (extval[0] == '+' || extval[0] == '-')
3095 appendStringInfo(buf, "(%s)", extval);
3096 else
3097 appendStringInfoString(buf, extval);
3098 if (strcspn(extval, "eE.") != strlen(extval))
3099 isfloat = true; /* it looks like a float */
3100 }
3101 else
3102 appendStringInfo(buf, "'%s'", extval);
3103 }
3104 break;
3105 case BITOID:
3106 case VARBITOID:
3107 appendStringInfo(buf, "B'%s'", extval);
3108 break;
3109 case BOOLOID:
3110 if (strcmp(extval, "t") == 0)
3111 appendStringInfoString(buf, "true");
3112 else
3113 appendStringInfoString(buf, "false");
3114 break;
3115 default:
3116 deparseStringLiteral(buf, extval);
3117 isstring = true;
3118 break;
3119 }
3120
3121 pfree(extval);
3122
3123 if (showtype == -1)
3124 return; /* never print type label */
3125
3126 /*
3127 * For showtype == 0, append ::typename unless the constant will be
3128 * implicitly typed as the right type when it is read in.
3129 *
3130 * XXX this code has to be kept in sync with the behavior of the parser,
3131 * especially make_const.
3132 */
3133 switch (node->consttype)
3134 {
3135 case BOOLOID:
3136 case INT4OID:
3137 case UNKNOWNOID:
3138 needlabel = false;
3139 break;
3140 case NUMERICOID:
3141 needlabel = !isfloat || (node->consttypmod >= 0);
3142 break;
3143 default:
3144 if (showtype == -2)
3145 {
3146 /* label unless we printed it as an untyped string */
3147 needlabel = !isstring;
3148 }
3149 else
3150 needlabel = true;
3151 break;
3152 }
3153 if (needlabel || showtype > 0)
3154 appendStringInfo(buf, "::%s",
3155 deparse_type_name(node->consttype,
3156 node->consttypmod));
3157}
3158
3159/*
3160 * Deparse given Param node.
3161 *
3162 * If we're generating the query "for real", add the Param to
3163 * context->params_list if it's not already present, and then use its index
3164 * in that list as the remote parameter number. During EXPLAIN, there's
3165 * no need to identify a parameter number.
3166 */
3167static void
3168deparseParam(Param *node, deparse_expr_cxt *context)
3169{
3170 if (context->params_list)
3171 {
3172 int pindex = 0;
3173 ListCell *lc;
3174
3175 /* find its index in params_list */
3176 foreach(lc, *context->params_list)
3177 {
3178 pindex++;
3179 if (equal(node, (Node *) lfirst(lc)))
3180 break;
3181 }
3182 if (lc == NULL)
3183 {
3184 /* not in list, so add it */
3185 pindex++;
3186 *context->params_list = lappend(*context->params_list, node);
3187 }
3188
3189 printRemoteParam(pindex, node->paramtype, node->paramtypmod, context);
3190 }
3191 else
3192 {
3193 printRemotePlaceholder(node->paramtype, node->paramtypmod, context);
3194 }
3195}
3196
3197/*
3198 * Deparse a container subscript expression.
3199 */
3200static void
3201deparseSubscriptingRef(SubscriptingRef *node, deparse_expr_cxt *context)
3202{
3203 StringInfo buf = context->buf;
3204 ListCell *lowlist_item;
3205 ListCell *uplist_item;
3206
3207 /* Always parenthesize the expression. */
3208 appendStringInfoChar(buf, '(');
3209
3210 /*
3211 * Deparse referenced array expression first. If that expression includes
3212 * a cast, we have to parenthesize to prevent the array subscript from
3213 * being taken as typename decoration. We can avoid that in the typical
3214 * case of subscripting a Var, but otherwise do it.
3215 */
3216 if (IsA(node->refexpr, Var))
3217 deparseExpr(node->refexpr, context);
3218 else
3219 {
3220 appendStringInfoChar(buf, '(');
3221 deparseExpr(node->refexpr, context);
3222 appendStringInfoChar(buf, ')');
3223 }
3224
3225 /* Deparse subscript expressions. */
3226 lowlist_item = list_head(node->reflowerindexpr); /* could be NULL */
3227 foreach(uplist_item, node->refupperindexpr)
3228 {
3229 appendStringInfoChar(buf, '[');
3230 if (lowlist_item)
3231 {
3232 deparseExpr(lfirst(lowlist_item), context);
3233 appendStringInfoChar(buf, ':');
3234 lowlist_item = lnext(node->reflowerindexpr, lowlist_item);
3235 }
3236 deparseExpr(lfirst(uplist_item), context);
3237 appendStringInfoChar(buf, ']');
3238 }
3239
3240 appendStringInfoChar(buf, ')');
3241}
3242
3243/*
3244 * Deparse a function call.
3245 */
3246static void
3247deparseFuncExpr(FuncExpr *node, deparse_expr_cxt *context)
3248{
3249 StringInfo buf = context->buf;
3250 bool use_variadic;
3251 bool first;
3252 ListCell *arg;
3253
3254 /*
3255 * If the function call came from an implicit coercion, then just show the
3256 * first argument.
3257 */
3258 if (node->funcformat == COERCE_IMPLICIT_CAST)
3259 {
3260 deparseExpr((Expr *) linitial(node->args), context);
3261 return;
3262 }
3263
3264 /*
3265 * If the function call came from a cast, then show the first argument
3266 * plus an explicit cast operation.
3267 */
3268 if (node->funcformat == COERCE_EXPLICIT_CAST)
3269 {
3270 Oid rettype = node->funcresulttype;
3271 int32 coercedTypmod;
3272
3273 /* Get the typmod if this is a length-coercion function */
3274 (void) exprIsLengthCoercion((Node *) node, &coercedTypmod);
3275
3276 deparseExpr((Expr *) linitial(node->args), context);
3277 appendStringInfo(buf, "::%s",
3278 deparse_type_name(rettype, coercedTypmod));
3279 return;
3280 }
3281
3282 /* Check if need to print VARIADIC (cf. ruleutils.c) */
3283 use_variadic = node->funcvariadic;
3284
3285 /*
3286 * Normal function: display as proname(args).
3287 */
3288 appendFunctionName(node->funcid, context);
3289 appendStringInfoChar(buf, '(');
3290
3291 /* ... and all the arguments */
3292 first = true;
3293 foreach(arg, node->args)
3294 {
3295 if (!first)
3296 appendStringInfoString(buf, ", ");
3297 if (use_variadic && lnext(node->args, arg) == NULL)
3298 appendStringInfoString(buf, "VARIADIC ");
3299 deparseExpr((Expr *) lfirst(arg), context);
3300 first = false;
3301 }
3302 appendStringInfoChar(buf, ')');
3303}
3304
3305/*
3306 * Deparse given operator expression. To avoid problems around
3307 * priority of operations, we always parenthesize the arguments.
3308 */
3309static void
3310deparseOpExpr(OpExpr *node, deparse_expr_cxt *context)
3311{
3312 StringInfo buf = context->buf;
3313 HeapTuple tuple;
3314 Form_pg_operator form;
3315 Expr *right;
3316 bool canSuppressRightConstCast = false;
3317 char oprkind;
3318
3319 /* Retrieve information about the operator from system catalog. */
3320 tuple = SearchSysCache1(OPEROID, ObjectIdGetDatum(node->opno));
3321 if (!HeapTupleIsValid(tuple))
3322 elog(ERROR, "cache lookup failed for operator %u", node->opno);
3323 form = (Form_pg_operator) GETSTRUCT(tuple);
3324 oprkind = form->oprkind;
3325
3326 /* Sanity check. */
3327 Assert((oprkind == 'l' && list_length(node->args) == 1) ||
3328 (oprkind == 'b' && list_length(node->args) == 2));
3329
3330 right = llast(node->args);
3331
3332 /* Always parenthesize the expression. */
3333 appendStringInfoChar(buf, '(');
3334
3335 /* Deparse left operand, if any. */
3336 if (oprkind == 'b')
3337 {
3338 Expr *left = linitial(node->args);
3339 Oid leftType = exprType((Node *) left);
3340 Oid rightType = exprType((Node *) right);
3341 bool canSuppressLeftConstCast = false;
3342
3343 /*
3344 * When considering a binary operator, if one operand is a Const that
3345 * can be printed as a bare string literal or NULL (i.e., it will look
3346 * like type UNKNOWN to the remote parser), the Const normally
3347 * receives an explicit cast to the operator's input type. However,
3348 * in Const-to-Var comparisons where both operands are of the same
3349 * type, we prefer to suppress the explicit cast, leaving the Const's
3350 * type resolution up to the remote parser. The remote's resolution
3351 * heuristic will assume that an unknown input type being compared to
3352 * a known input type is of that known type as well.
3353 *
3354 * This hack allows some cases to succeed where a remote column is
3355 * declared with a different type in the local (foreign) table. By
3356 * emitting "foreigncol = 'foo'" not "foreigncol = 'foo'::text" or the
3357 * like, we allow the remote parser to pick an "=" operator that's
3358 * compatible with whatever type the remote column really is, such as
3359 * an enum.
3360 *
3361 * We allow cast suppression to happen only when the other operand is
3362 * a plain foreign Var. Although the remote's unknown-type heuristic
3363 * would apply to other cases just as well, we would be taking a
3364 * bigger risk that the inferred type is something unexpected. With
3365 * this restriction, if anything goes wrong it's the user's fault for
3366 * not declaring the local column with the same type as the remote
3367 * column.
3368 */
3369 if (leftType == rightType)
3370 {
3371 if (IsA(left, Const))
3372 canSuppressLeftConstCast = isPlainForeignVar(right, context);
3373 else if (IsA(right, Const))
3374 canSuppressRightConstCast = isPlainForeignVar(left, context);
3375 }
3376
3377 if (canSuppressLeftConstCast)
3378 deparseConst((Const *) left, context, -2);
3379 else
3380 deparseExpr(left, context);
3381
3382 appendStringInfoChar(buf, ' ');
3383 }
3384
3385 /* Deparse operator name. */
3386 deparseOperatorName(buf, form);
3387
3388 /* Deparse right operand. */
3389 appendStringInfoChar(buf, ' ');
3390
3391 if (canSuppressRightConstCast)
3392 deparseConst((Const *) right, context, -2);
3393 else
3394 deparseExpr(right, context);
3395
3396 appendStringInfoChar(buf, ')');
3397
3398 ReleaseSysCache(tuple);
3399}
3400
3401/*
3402 * Will "node" deparse as a plain foreign Var?
3403 */
3404static bool
3405isPlainForeignVar(Expr *node, deparse_expr_cxt *context)
3406{
3407 /*
3408 * We allow the foreign Var to have an implicit RelabelType, mainly so
3409 * that this'll work with varchar columns. Note that deparseRelabelType
3410 * will not print such a cast, so we're not breaking the restriction that
3411 * the expression print as a plain Var. We won't risk it for an implicit
3412 * cast that requires a function, nor for non-implicit RelabelType; such
3413 * cases seem too likely to involve semantics changes compared to what
3414 * would happen on the remote side.
3415 */
3416 if (IsA(node, RelabelType) &&
3417 ((RelabelType *) node)->relabelformat == COERCE_IMPLICIT_CAST)
3418 node = ((RelabelType *) node)->arg;
3419
3420 if (IsA(node, Var))
3421 {
3422 /*
3423 * The Var must be one that'll deparse as a foreign column reference
3424 * (cf. deparseVar).
3425 */
3426 Var *var = (Var *) node;
3427 Relids relids = context->scanrel->relids;
3428
3429 if (bms_is_member(var->varno, relids) && var->varlevelsup == 0)
3430 return true;
3431 }
3432
3433 return false;
3434}
3435
3436/*
3437 * Print the name of an operator.
3438 */
3439static void
3440deparseOperatorName(StringInfo buf, Form_pg_operator opform)
3441{
3442 char *opname;
3443
3444 /* opname is not a SQL identifier, so we should not quote it. */
3445 opname = NameStr(opform->oprname);
3446
3447 /* Print schema name only if it's not pg_catalog */
3448 if (opform->oprnamespace != PG_CATALOG_NAMESPACE)
3449 {
3450 const char *opnspname;
3451
3452 opnspname = get_namespace_name(opform->oprnamespace);
3453 /* Print fully qualified operator name. */
3454 appendStringInfo(buf, "OPERATOR(%s.%s)",
3455 quote_identifier(opnspname), opname);
3456 }
3457 else
3458 {
3459 /* Just print operator name. */
3460 appendStringInfoString(buf, opname);
3461 }
3462}
3463
3464/*
3465 * Deparse IS DISTINCT FROM.
3466 */
3467static void
3468deparseDistinctExpr(DistinctExpr *node, deparse_expr_cxt *context)
3469{
3470 StringInfo buf = context->buf;
3471
3472 Assert(list_length(node->args) == 2);
3473
3474 appendStringInfoChar(buf, '(');
3475 deparseExpr(linitial(node->args), context);
3476 appendStringInfoString(buf, " IS DISTINCT FROM ");
3477 deparseExpr(lsecond(node->args), context);
3478 appendStringInfoChar(buf, ')');
3479}
3480
3481/*
3482 * Deparse given ScalarArrayOpExpr expression. To avoid problems
3483 * around priority of operations, we always parenthesize the arguments.
3484 */
3485static void
3486deparseScalarArrayOpExpr(ScalarArrayOpExpr *node, deparse_expr_cxt *context)
3487{
3488 StringInfo buf = context->buf;
3489 HeapTuple tuple;
3490 Form_pg_operator form;
3491 Expr *arg1;
3492 Expr *arg2;
3493
3494 /* Retrieve information about the operator from system catalog. */
3495 tuple = SearchSysCache1(OPEROID, ObjectIdGetDatum(node->opno));
3496 if (!HeapTupleIsValid(tuple))
3497 elog(ERROR, "cache lookup failed for operator %u", node->opno);
3498 form = (Form_pg_operator) GETSTRUCT(tuple);
3499
3500 /* Sanity check. */
3501 Assert(list_length(node->args) == 2);
3502
3503 /* Always parenthesize the expression. */
3504 appendStringInfoChar(buf, '(');
3505
3506 /* Deparse left operand. */
3507 arg1 = linitial(node->args);
3508 deparseExpr(arg1, context);
3509 appendStringInfoChar(buf, ' ');
3510
3511 /* Deparse operator name plus decoration. */
3512 deparseOperatorName(buf, form);
3513 appendStringInfo(buf, " %s (", node->useOr ? "ANY" : "ALL");
3514
3515 /* Deparse right operand. */
3516 arg2 = lsecond(node->args);
3517 deparseExpr(arg2, context);
3518
3519 appendStringInfoChar(buf, ')');
3520
3521 /* Always parenthesize the expression. */
3522 appendStringInfoChar(buf, ')');
3523
3524 ReleaseSysCache(tuple);
3525}
3526
3527/*
3528 * Deparse a RelabelType (binary-compatible cast) node.
3529 */
3530static void
3531deparseRelabelType(RelabelType *node, deparse_expr_cxt *context)
3532{
3533 deparseExpr(node->arg, context);
3534 if (node->relabelformat != COERCE_IMPLICIT_CAST)
3535 appendStringInfo(context->buf, "::%s",
3536 deparse_type_name(node->resulttype,
3537 node->resulttypmod));
3538}
3539
3540/*
3541 * Deparse an ArrayCoerceExpr (array-type conversion) node.
3542 */
3543static void
3544deparseArrayCoerceExpr(ArrayCoerceExpr *node, deparse_expr_cxt *context)
3545{
3546 deparseExpr(node->arg, context);
3547
3548 /*
3549 * No difference how to deparse explicit cast, but if we omit implicit
3550 * cast in the query, it'll be more user-friendly
3551 */
3552 if (node->coerceformat != COERCE_IMPLICIT_CAST)
3553 appendStringInfo(context->buf, "::%s",
3554 deparse_type_name(node->resulttype,
3555 node->resulttypmod));
3556}
3557
3558/*
3559 * Deparse a BoolExpr node.
3560 */
3561static void
3562deparseBoolExpr(BoolExpr *node, deparse_expr_cxt *context)
3563{
3564 StringInfo buf = context->buf;
3565 const char *op = NULL; /* keep compiler quiet */
3566 bool first;
3567 ListCell *lc;
3568
3569 switch (node->boolop)
3570 {
3571 case AND_EXPR:
3572 op = "AND";
3573 break;
3574 case OR_EXPR:
3575 op = "OR";
3576 break;
3577 case NOT_EXPR:
3578 appendStringInfoString(buf, "(NOT ");
3579 deparseExpr(linitial(node->args), context);
3580 appendStringInfoChar(buf, ')');
3581 return;
3582 }
3583
3584 appendStringInfoChar(buf, '(');
3585 first = true;
3586 foreach(lc, node->args)
3587 {
3588 if (!first)
3589 appendStringInfo(buf, " %s ", op);
3590 deparseExpr((Expr *) lfirst(lc), context);
3591 first = false;
3592 }
3593 appendStringInfoChar(buf, ')');
3594}
3595
3596/*
3597 * Deparse IS [NOT] NULL expression.
3598 */
3599static void
3600deparseNullTest(NullTest *node, deparse_expr_cxt *context)
3601{
3602 StringInfo buf = context->buf;
3603
3604 appendStringInfoChar(buf, '(');
3605 deparseExpr(node->arg, context);
3606
3607 /*
3608 * For scalar inputs, we prefer to print as IS [NOT] NULL, which is
3609 * shorter and traditional. If it's a rowtype input but we're applying a
3610 * scalar test, must print IS [NOT] DISTINCT FROM NULL to be semantically
3611 * correct.
3612 */
3613 if (node->argisrow || !type_is_rowtype(exprType((Node *) node->arg)))
3614 {
3615 if (node->nulltesttype == IS_NULL)
3616 appendStringInfoString(buf, " IS NULL)");
3617 else
3618 appendStringInfoString(buf, " IS NOT NULL)");
3619 }
3620 else
3621 {
3622 if (node->nulltesttype == IS_NULL)
3623 appendStringInfoString(buf, " IS NOT DISTINCT FROM NULL)");
3624 else
3625 appendStringInfoString(buf, " IS DISTINCT FROM NULL)");
3626 }
3627}
3628
3629/*
3630 * Deparse CASE expression
3631 */
3632static void
3633deparseCaseExpr(CaseExpr *node, deparse_expr_cxt *context)
3634{
3635 StringInfo buf = context->buf;
3636 ListCell *lc;
3637
3638 appendStringInfoString(buf, "(CASE");
3639
3640 /* If this is a CASE arg WHEN then emit the arg expression */
3641 if (node->arg != NULL)
3642 {
3643 appendStringInfoChar(buf, ' ');
3644 deparseExpr(node->arg, context);
3645 }
3646
3647 /* Add each condition/result of the CASE clause */
3648 foreach(lc, node->args)
3649 {
3650 CaseWhen *whenclause = (CaseWhen *) lfirst(lc);
3651
3652 /* WHEN */
3653 appendStringInfoString(buf, " WHEN ");
3654 if (node->arg == NULL) /* CASE WHEN */
3655 deparseExpr(whenclause->expr, context);
3656 else /* CASE arg WHEN */
3657 {
3658 /* Ignore the CaseTestExpr and equality operator. */
3659 deparseExpr(lsecond(castNode(OpExpr, whenclause->expr)->args),
3660 context);
3661 }
3662
3663 /* THEN */
3664 appendStringInfoString(buf, " THEN ");
3665 deparseExpr(whenclause->result, context);
3666 }
3667
3668 /* add ELSE if present */
3669 if (node->defresult != NULL)
3670 {
3671 appendStringInfoString(buf, " ELSE ");
3672 deparseExpr(node->defresult, context);
3673 }
3674
3675 /* append END */
3676 appendStringInfoString(buf, " END)");
3677}
3678
3679/*
3680 * Deparse ARRAY[...] construct.
3681 */
3682static void
3683deparseArrayExpr(ArrayExpr *node, deparse_expr_cxt *context)
3684{
3685 StringInfo buf = context->buf;
3686 bool first = true;
3687 ListCell *lc;
3688
3689 appendStringInfoString(buf, "ARRAY[");
3690 foreach(lc, node->elements)
3691 {
3692 if (!first)
3693 appendStringInfoString(buf, ", ");
3694 deparseExpr(lfirst(lc), context);
3695 first = false;
3696 }
3697 appendStringInfoChar(buf, ']');
3698
3699 /* If the array is empty, we need an explicit cast to the array type. */
3700 if (node->elements == NIL)
3701 appendStringInfo(buf, "::%s",
3702 deparse_type_name(node->array_typeid, -1));
3703}
3704
3705/*
3706 * Deparse an Aggref node.
3707 */
3708static void
3709deparseAggref(Aggref *node, deparse_expr_cxt *context)
3710{
3711 StringInfo buf = context->buf;
3712 bool use_variadic;
3713
3714 /* Only basic, non-split aggregation accepted. */
3715 Assert(node->aggsplit == AGGSPLIT_SIMPLE);
3716
3717 /* Check if need to print VARIADIC (cf. ruleutils.c) */
3718 use_variadic = node->aggvariadic;
3719
3720 /* Find aggregate name from aggfnoid which is a pg_proc entry */
3721 appendFunctionName(node->aggfnoid, context);
3722 appendStringInfoChar(buf, '(');
3723
3724 /* Add DISTINCT */
3725 appendStringInfoString(buf, (node->aggdistinct != NIL) ? "DISTINCT " : "");
3726
3727 if (AGGKIND_IS_ORDERED_SET(node->aggkind))
3728 {
3729 /* Add WITHIN GROUP (ORDER BY ..) */
3730 ListCell *arg;
3731 bool first = true;
3732
3733 Assert(!node->aggvariadic);
3734 Assert(node->aggorder != NIL);
3735
3736 foreach(arg, node->aggdirectargs)
3737 {
3738 if (!first)
3739 appendStringInfoString(buf, ", ");
3740 first = false;
3741
3742 deparseExpr((Expr *) lfirst(arg), context);
3743 }
3744
3745 appendStringInfoString(buf, ") WITHIN GROUP (ORDER BY ");
3746 appendAggOrderBy(node->aggorder, node->args, context);
3747 }
3748 else
3749 {
3750 /* aggstar can be set only in zero-argument aggregates */
3751 if (node->aggstar)
3752 appendStringInfoChar(buf, '*');
3753 else
3754 {
3755 ListCell *arg;
3756 bool first = true;
3757
3758 /* Add all the arguments */
3759 foreach(arg, node->args)
3760 {
3761 TargetEntry *tle = (TargetEntry *) lfirst(arg);
3762 Node *n = (Node *) tle->expr;
3763
3764 if (tle->resjunk)
3765 continue;
3766
3767 if (!first)
3768 appendStringInfoString(buf, ", ");
3769 first = false;
3770
3771 /* Add VARIADIC */
3772 if (use_variadic && lnext(node->args, arg) == NULL)
3773 appendStringInfoString(buf, "VARIADIC ");
3774
3775 deparseExpr((Expr *) n, context);
3776 }
3777 }
3778
3779 /* Add ORDER BY */
3780 if (node->aggorder != NIL)
3781 {
3782 appendStringInfoString(buf, " ORDER BY ");
3783 appendAggOrderBy(node->aggorder, node->args, context);
3784 }
3785 }
3786
3787 /* Add FILTER (WHERE ..) */
3788 if (node->aggfilter != NULL)
3789 {
3790 appendStringInfoString(buf, ") FILTER (WHERE ");
3791 deparseExpr((Expr *) node->aggfilter, context);
3792 }
3793
3794 appendStringInfoChar(buf, ')');
3795}
3796
3797/*
3798 * Append ORDER BY within aggregate function.
3799 */
3800static void
3801appendAggOrderBy(List *orderList, List *targetList, deparse_expr_cxt *context)
3802{
3803 StringInfo buf = context->buf;
3804 ListCell *lc;
3805 bool first = true;
3806
3807 foreach(lc, orderList)
3808 {
3809 SortGroupClause *srt = (SortGroupClause *) lfirst(lc);
3810 Node *sortexpr;
3811
3812 if (!first)
3813 appendStringInfoString(buf, ", ");
3814 first = false;
3815
3816 /* Deparse the sort expression proper. */
3817 sortexpr = deparseSortGroupClause(srt->tleSortGroupRef, targetList,
3818 false, context);
3819 /* Add decoration as needed. */
3820 appendOrderBySuffix(srt->sortop, exprType(sortexpr), srt->nulls_first,
3821 context);
3822 }
3823}
3824
3825/*
3826 * Append the ASC, DESC, USING <OPERATOR> and NULLS FIRST / NULLS LAST parts
3827 * of an ORDER BY clause.
3828 */
3829static void
3830appendOrderBySuffix(Oid sortop, Oid sortcoltype, bool nulls_first,
3831 deparse_expr_cxt *context)
3832{
3833 StringInfo buf = context->buf;
3834 TypeCacheEntry *typentry;
3835
3836 /* See whether operator is default < or > for sort expr's datatype. */
3837 typentry = lookup_type_cache(sortcoltype,
3838 TYPECACHE_LT_OPR | TYPECACHE_GT_OPR);
3839
3840 if (sortop == typentry->lt_opr)
3841 appendStringInfoString(buf, " ASC");
3842 else if (sortop == typentry->gt_opr)
3843 appendStringInfoString(buf, " DESC");
3844 else
3845 {
3846 HeapTuple opertup;
3847 Form_pg_operator operform;
3848
3849 appendStringInfoString(buf, " USING ");
3850
3851 /* Append operator name. */
3852 opertup = SearchSysCache1(OPEROID, ObjectIdGetDatum(sortop));
3853 if (!HeapTupleIsValid(opertup))
3854 elog(ERROR, "cache lookup failed for operator %u", sortop);
3855 operform = (Form_pg_operator) GETSTRUCT(opertup);
3856 deparseOperatorName(buf, operform);
3857 ReleaseSysCache(opertup);
3858 }
3859
3860 if (nulls_first)
3861 appendStringInfoString(buf, " NULLS FIRST");
3862 else
3863 appendStringInfoString(buf, " NULLS LAST");
3864}
3865
3866/*
3867 * Print the representation of a parameter to be sent to the remote side.
3868 *
3869 * Note: we always label the Param's type explicitly rather than relying on
3870 * transmitting a numeric type OID in PQsendQueryParams(). This allows us to
3871 * avoid assuming that types have the same OIDs on the remote side as they
3872 * do locally --- they need only have the same names.
3873 */
3874static void
3875printRemoteParam(int paramindex, Oid paramtype, int32 paramtypmod,
3876 deparse_expr_cxt *context)
3877{
3878 StringInfo buf = context->buf;
3879 char *ptypename = deparse_type_name(paramtype, paramtypmod);
3880
3881 appendStringInfo(buf, "$%d::%s", paramindex, ptypename);
3882}
3883
3884/*
3885 * Print the representation of a placeholder for a parameter that will be
3886 * sent to the remote side at execution time.
3887 *
3888 * This is used when we're just trying to EXPLAIN the remote query.
3889 * We don't have the actual value of the runtime parameter yet, and we don't
3890 * want the remote planner to generate a plan that depends on such a value
3891 * anyway. Thus, we can't do something simple like "$1::paramtype".
3892 * Instead, we emit "((SELECT null::paramtype)::paramtype)".
3893 * In all extant versions of Postgres, the planner will see that as an unknown
3894 * constant value, which is what we want. This might need adjustment if we
3895 * ever make the planner flatten scalar subqueries. Note: the reason for the
3896 * apparently useless outer cast is to ensure that the representation as a
3897 * whole will be parsed as an a_expr and not a select_with_parens; the latter
3898 * would do the wrong thing in the context "x = ANY(...)".
3899 */
3900static void
3901printRemotePlaceholder(Oid paramtype, int32 paramtypmod,
3902 deparse_expr_cxt *context)
3903{
3904 StringInfo buf = context->buf;
3905 char *ptypename = deparse_type_name(paramtype, paramtypmod);
3906
3907 appendStringInfo(buf, "((SELECT null::%s)::%s)", ptypename, ptypename);
3908}
3909
3910/*
3911 * Deparse GROUP BY clause.
3912 */
3913static void
3914appendGroupByClause(List *tlist, deparse_expr_cxt *context)
3915{
3916 StringInfo buf = context->buf;
3917 Query *query = context->root->parse;
3918 ListCell *lc;
3919 bool first = true;
3920
3921 /* Nothing to be done, if there's no GROUP BY clause in the query. */
3922 if (!query->groupClause)
3923 return;
3924
3925 appendStringInfoString(buf, " GROUP BY ");
3926
3927 /*
3928 * Queries with grouping sets are not pushed down, so we don't expect
3929 * grouping sets here.
3930 */
3931 Assert(!query->groupingSets);
3932
3933 /*
3934 * We intentionally print query->groupClause not processed_groupClause,
3935 * leaving it to the remote planner to get rid of any redundant GROUP BY
3936 * items again. This is necessary in case processed_groupClause reduced
3937 * to empty, and in any case the redundancy situation on the remote might
3938 * be different than what we think here.
3939 */
3940 foreach(lc, query->groupClause)
3941 {
3942 SortGroupClause *grp = (SortGroupClause *) lfirst(lc);
3943
3944 if (!first)
3945 appendStringInfoString(buf, ", ");
3946 first = false;
3947
3948 deparseSortGroupClause(grp->tleSortGroupRef, tlist, true, context);
3949 }
3950}
3951
3952/*
3953 * Deparse ORDER BY clause defined by the given pathkeys.
3954 *
3955 * The clause should use Vars from context->scanrel if !has_final_sort,
3956 * or from context->foreignrel's targetlist if has_final_sort.
3957 *
3958 * We find a suitable pathkey expression (some earlier step
3959 * should have verified that there is one) and deparse it.
3960 */
3961static void
3962appendOrderByClause(List *pathkeys, bool has_final_sort,
3963 deparse_expr_cxt *context)
3964{
3965 ListCell *lcell;
3966 int nestlevel;
3967 StringInfo buf = context->buf;
3968 bool gotone = false;
3969
3970 /* Make sure any constants in the exprs are printed portably */
3971 nestlevel = set_transmission_modes();
3972
3973 foreach(lcell, pathkeys)
3974 {
3975 PathKey *pathkey = lfirst(lcell);
3976 EquivalenceMember *em;
3977 Expr *em_expr;
3978 Oid oprid;
3979
3980 if (has_final_sort)
3981 {
3982 /*
3983 * By construction, context->foreignrel is the input relation to
3984 * the final sort.
3985 */
3986 em = find_em_for_rel_target(context->root,
3987 pathkey->pk_eclass,
3988 context->foreignrel);
3989 }
3990 else
3991 em = find_em_for_rel(context->root,
3992 pathkey->pk_eclass,
3993 context->scanrel);
3994
3995 /*
3996 * We don't expect any error here; it would mean that shippability
3997 * wasn't verified earlier. For the same reason, we don't recheck
3998 * shippability of the sort operator.
3999 */
4000 if (em == NULL)
4001 elog(ERROR, "could not find pathkey item to sort");
4002
4003 em_expr = em->em_expr;
4004
4005 /*
4006 * If the member is a Const expression then we needn't add it to the
4007 * ORDER BY clause. This can happen in UNION ALL queries where the
4008 * union child targetlist has a Const. Adding these would be
4009 * wasteful, but also, for INT columns, an integer literal would be
4010 * seen as an ordinal column position rather than a value to sort by.
4011 * deparseConst() does have code to handle this, but it seems less
4012 * effort on all accounts just to skip these for ORDER BY clauses.
4013 */
4014 if (IsA(em_expr, Const))
4015 continue;
4016
4017 if (!gotone)
4018 {
4019 appendStringInfoString(buf, " ORDER BY ");
4020 gotone = true;
4021 }
4022 else
4023 appendStringInfoString(buf, ", ");
4024
4025 /*
4026 * Lookup the operator corresponding to the compare type in the
4027 * opclass. The datatype used by the opfamily is not necessarily the
4028 * same as the expression type (for array types for example).
4029 */
4030 oprid = get_opfamily_member_for_cmptype(pathkey->pk_opfamily,
4031 em->em_datatype,
4032 em->em_datatype,
4033 pathkey->pk_cmptype);
4034 if (!OidIsValid(oprid))
4035 elog(ERROR, "missing operator %d(%u,%u) in opfamily %u",
4036 pathkey->pk_cmptype, em->em_datatype, em->em_datatype,
4037 pathkey->pk_opfamily);
4038
4039 deparseExpr(em_expr, context);
4040
4041 /*
4042 * Here we need to use the expression's actual type to discover
4043 * whether the desired operator will be the default or not.
4044 */
4045 appendOrderBySuffix(oprid, exprType((Node *) em_expr),
4046 pathkey->pk_nulls_first, context);
4047
4048 }
4049 reset_transmission_modes(nestlevel);
4050}
4051
4052/*
4053 * Deparse LIMIT/OFFSET clause.
4054 */
4055static void
4056appendLimitClause(deparse_expr_cxt *context)
4057{
4058 PlannerInfo *root = context->root;
4059 StringInfo buf = context->buf;
4060 int nestlevel;
4061
4062 /* Make sure any constants in the exprs are printed portably */
4063 nestlevel = set_transmission_modes();
4064
4065 if (root->parse->limitCount)
4066 {
4067 appendStringInfoString(buf, " LIMIT ");
4068 deparseExpr((Expr *) root->parse->limitCount, context);
4069 }
4070 if (root->parse->limitOffset)
4071 {
4072 appendStringInfoString(buf, " OFFSET ");
4073 deparseExpr((Expr *) root->parse->limitOffset, context);
4074 }
4075
4076 reset_transmission_modes(nestlevel);
4077}
4078
4079/*
4080 * appendFunctionName
4081 * Deparses function name from given function oid.
4082 */
4083static void
4084appendFunctionName(Oid funcid, deparse_expr_cxt *context)
4085{
4086 StringInfo buf = context->buf;
4087 HeapTuple proctup;
4088 Form_pg_proc procform;
4089 const char *proname;
4090
4091 proctup = SearchSysCache1(PROCOID, ObjectIdGetDatum(funcid));
4092 if (!HeapTupleIsValid(proctup))
4093 elog(ERROR, "cache lookup failed for function %u", funcid);
4094 procform = (Form_pg_proc) GETSTRUCT(proctup);
4095
4096 /* Print schema name only if it's not pg_catalog */
4097 if (procform->pronamespace != PG_CATALOG_NAMESPACE)
4098 {
4099 const char *schemaname;
4100
4101 schemaname = get_namespace_name(procform->pronamespace);
4102 appendStringInfo(buf, "%s.", quote_identifier(schemaname));
4103 }
4104
4105 /* Always print the function name */
4106 proname = NameStr(procform->proname);
4107 appendStringInfoString(buf, quote_identifier(proname));
4108
4109 ReleaseSysCache(proctup);
4110}
4111
4112/*
4113 * Appends a sort or group clause.
4114 *
4115 * Like get_rule_sortgroupclause(), returns the expression tree, so caller
4116 * need not find it again.
4117 */
4118static Node *
4119deparseSortGroupClause(Index ref, List *tlist, bool force_colno,
4120 deparse_expr_cxt *context)
4121{
4122 StringInfo buf = context->buf;
4123 TargetEntry *tle;
4124 Expr *expr;
4125
4126 tle = get_sortgroupref_tle(ref, tlist);
4127 expr = tle->expr;
4128
4129 if (force_colno)
4130 {
4131 /* Use column-number form when requested by caller. */
4132 Assert(!tle->resjunk);
4133 appendStringInfo(buf, "%d", tle->resno);
4134 }
4135 else if (expr && IsA(expr, Const))
4136 {
4137 /*
4138 * Force a typecast here so that we don't emit something like "GROUP
4139 * BY 2", which will be misconstrued as a column position rather than
4140 * a constant.
4141 */
4142 deparseConst((Const *) expr, context, 1);
4143 }
4144 else if (!expr || IsA(expr, Var))
4145 deparseExpr(expr, context);
4146 else
4147 {
4148 /* Always parenthesize the expression. */
4149 appendStringInfoChar(buf, '(');
4150 deparseExpr(expr, context);
4151 appendStringInfoChar(buf, ')');
4152 }
4153
4154 return (Node *) expr;
4155}
4156
4157
4158/*
4159 * Returns true if given Var is deparsed as a subquery output column, in
4160 * which case, *relno and *colno are set to the IDs for the relation and
4161 * column alias to the Var provided by the subquery.
4162 */
4163static bool
4164is_subquery_var(Var *node, RelOptInfo *foreignrel, int *relno, int *colno)
4165{
4166 PgFdwRelationInfo *fpinfo = (PgFdwRelationInfo *) foreignrel->fdw_private;
4167 RelOptInfo *outerrel = fpinfo->outerrel;
4168 RelOptInfo *innerrel = fpinfo->innerrel;
4169
4170 /* Should only be called in these cases. */
4171 Assert(IS_SIMPLE_REL(foreignrel) || IS_JOIN_REL(foreignrel));
4172
4173 /*
4174 * If the given relation isn't a join relation, it doesn't have any lower
4175 * subqueries, so the Var isn't a subquery output column.
4176 */
4177 if (!IS_JOIN_REL(foreignrel))
4178 return false;
4179
4180 /*
4181 * If the Var doesn't belong to any lower subqueries, it isn't a subquery
4182 * output column.
4183 */
4184 if (!bms_is_member(node->varno, fpinfo->lower_subquery_rels))
4185 return false;
4186
4187 if (bms_is_member(node->varno, outerrel->relids))
4188 {
4189 /*
4190 * If outer relation is deparsed as a subquery, the Var is an output
4191 * column of the subquery; get the IDs for the relation/column alias.
4192 */
4193 if (fpinfo->make_outerrel_subquery)
4194 {
4195 get_relation_column_alias_ids(node, outerrel, relno, colno);
4196 return true;
4197 }
4198
4199 /* Otherwise, recurse into the outer relation. */
4200 return is_subquery_var(node, outerrel, relno, colno);
4201 }
4202 else
4203 {
4204 Assert(bms_is_member(node->varno, innerrel->relids));
4205
4206 /*
4207 * If inner relation is deparsed as a subquery, the Var is an output
4208 * column of the subquery; get the IDs for the relation/column alias.
4209 */
4210 if (fpinfo->make_innerrel_subquery)
4211 {
4212 get_relation_column_alias_ids(node, innerrel, relno, colno);
4213 return true;
4214 }
4215
4216 /* Otherwise, recurse into the inner relation. */
4217 return is_subquery_var(node, innerrel, relno, colno);
4218 }
4219}
4220
4221/*
4222 * Get the IDs for the relation and column alias to given Var belonging to
4223 * given relation, which are returned into *relno and *colno.
4224 */
4225static void
4226get_relation_column_alias_ids(Var *node, RelOptInfo *foreignrel,
4227 int *relno, int *colno)
4228{
4229 PgFdwRelationInfo *fpinfo = (PgFdwRelationInfo *) foreignrel->fdw_private;
4230 int i;
4231 ListCell *lc;
4232
4233 /* Get the relation alias ID */
4234 *relno = fpinfo->relation_index;
4235
4236 /* Get the column alias ID */
4237 i = 1;
4238 foreach(lc, foreignrel->reltarget->exprs)
4239 {
4240 Var *tlvar = (Var *) lfirst(lc);
4241
4242 /*
4243 * Match reltarget entries only on varno/varattno. Ideally there
4244 * would be some cross-check on varnullingrels, but it's unclear what
4245 * to do exactly; we don't have enough context to know what that value
4246 * should be.
4247 */
4248 if (IsA(tlvar, Var) &&
4249 tlvar->varno == node->varno &&
4250 tlvar->varattno == node->varattno)
4251 {
4252 *colno = i;
4253 return;
4254 }
4255 i++;
4256 }
4257
4258 /* Shouldn't get here */
4259 elog(ERROR, "unexpected expression in subquery output");
4260}
AttrNumber
int16 AttrNumber
Definition: attnum.h:21
bms_make_singleton
Bitmapset * bms_make_singleton(int x)
Definition: bitmapset.c:216
bms_next_member
int bms_next_member(const Bitmapset *a, int prevbit)
Definition: bitmapset.c:1306
bms_free
void bms_free(Bitmapset *a)
Definition: bitmapset.c:239
bms_is_member
bool bms_is_member(int x, const Bitmapset *a)
Definition: bitmapset.c:510
bms_add_member
Bitmapset * bms_add_member(Bitmapset *a, int x)
Definition: bitmapset.c:815
bms_membership
BMS_Membership bms_membership(const Bitmapset *a)
Definition: bitmapset.c:781
BMS_MULTIPLE
@ BMS_MULTIPLE
Definition: bitmapset.h:73
FORMAT_TYPE_TYPEMOD_GIVEN
#define FORMAT_TYPE_TYPEMOD_GIVEN
Definition: builtins.h:124
FORMAT_TYPE_FORCE_QUALIFY
#define FORMAT_TYPE_FORCE_QUALIFY
Definition: builtins.h:126
NameStr
#define NameStr(name)
Definition: c.h:756
bits16
uint16 bits16
Definition: c.h:551
ESCAPE_STRING_SYNTAX
#define ESCAPE_STRING_SYNTAX
Definition: c.h:1156
SQL_STR_DOUBLE
#define SQL_STR_DOUBLE(ch, escape_backslash)
Definition: c.h:1153
int32
int32_t int32
Definition: c.h:539
Index
unsigned int Index
Definition: c.h:624
OidIsValid
#define OidIsValid(objectId)
Definition: c.h:779
contain_mutable_functions
bool contain_mutable_functions(Node *clause)
Definition: clauses.c:380
defGetString
char * defGetString(DefElem *def)
Definition: define.c:35
deparseArrayCoerceExpr
static void deparseArrayCoerceExpr(ArrayCoerceExpr *node, deparse_expr_cxt *context)
Definition: deparse.c:3544
deparseRangeTblRef
static void deparseRangeTblRef(StringInfo buf, PlannerInfo *root, RelOptInfo *foreignrel, bool make_subquery, Index ignore_rel, List **ignore_conds, List **additional_conds, List **params_list)
Definition: deparse.c:2039
deparseCaseExpr
static void deparseCaseExpr(CaseExpr *node, deparse_expr_cxt *context)
Definition: deparse.c:3633
deparseAnalyzeSizeSql
void deparseAnalyzeSizeSql(StringInfo buf, Relation rel)
Definition: deparse.c:2530
deparseBoolExpr
static void deparseBoolExpr(BoolExpr *node, deparse_expr_cxt *context)
Definition: deparse.c:3562
appendGroupByClause
static void appendGroupByClause(List *tlist, deparse_expr_cxt *context)
Definition: deparse.c:3914
deparseTargetList
static void deparseTargetList(StringInfo buf, RangeTblEntry *rte, Index rtindex, Relation rel, bool is_returning, Bitmapset *attrs_used, bool qualify_col, List **retrieved_attrs)
Definition: deparse.c:1438
SUBQUERY_REL_ALIAS_PREFIX
#define SUBQUERY_REL_ALIAS_PREFIX
Definition: deparse.c:113
deparseFromExpr
static void deparseFromExpr(List *quals, deparse_expr_cxt *context)
Definition: deparse.c:1406
deparseSortGroupClause
static Node * deparseSortGroupClause(Index ref, List *tlist, bool force_colno, deparse_expr_cxt *context)
Definition: deparse.c:4119
deparseLockingClause
static void deparseLockingClause(deparse_expr_cxt *context)
Definition: deparse.c:1512
get_jointype_name
const char * get_jointype_name(JoinType jointype)
Definition: deparse.c:1672
deparseAnalyzeInfoSql
void deparseAnalyzeInfoSql(StringInfo buf, Relation rel)
Definition: deparse.c:2552
deparseAggref
static void deparseAggref(Aggref *node, deparse_expr_cxt *context)
Definition: deparse.c:3709
appendOrderBySuffix
static void appendOrderBySuffix(Oid sortop, Oid sortcoltype, bool nulls_first, deparse_expr_cxt *context)
Definition: deparse.c:3830
deparseDirectDeleteSql
void deparseDirectDeleteSql(StringInfo buf, PlannerInfo *root, Index rtindex, Relation rel, RelOptInfo *foreignrel, List *remote_conds, List **params_list, List *returningList, List **retrieved_attrs)
Definition: deparse.c:2422
REL_ALIAS_PREFIX
#define REL_ALIAS_PREFIX
Definition: deparse.c:109
deparseDirectUpdateSql
void deparseDirectUpdateSql(StringInfo buf, PlannerInfo *root, Index rtindex, Relation rel, RelOptInfo *foreignrel, List *targetlist, List *targetAttrs, List *remote_conds, List **params_list, List *returningList, List **retrieved_attrs)
Definition: deparse.c:2307
deparse_expr_cxt
struct deparse_expr_cxt deparse_expr_cxt
get_relation_column_alias_ids
static void get_relation_column_alias_ids(Var *node, RelOptInfo *foreignrel, int *relno, int *colno)
Definition: deparse.c:4226
FDWCollateState
FDWCollateState
Definition: deparse.c:80
FDW_COLLATE_SAFE
@ FDW_COLLATE_SAFE
Definition: deparse.c:84
FDW_COLLATE_UNSAFE
@ FDW_COLLATE_UNSAFE
Definition: deparse.c:85
FDW_COLLATE_NONE
@ FDW_COLLATE_NONE
Definition: deparse.c:81
printRemoteParam
static void printRemoteParam(int paramindex, Oid paramtype, int32 paramtypmod, deparse_expr_cxt *context)
Definition: deparse.c:3875
is_subquery_var
static bool is_subquery_var(Var *node, RelOptInfo *foreignrel, int *relno, int *colno)
Definition: deparse.c:4164
is_foreign_param
bool is_foreign_param(PlannerInfo *root, RelOptInfo *baserel, Expr *expr)
Definition: deparse.c:1115
printRemotePlaceholder
static void printRemotePlaceholder(Oid paramtype, int32 paramtypmod, deparse_expr_cxt *context)
Definition: deparse.c:3901
appendOrderByClause
static void appendOrderByClause(List *pathkeys, bool has_final_sort, deparse_expr_cxt *context)
Definition: deparse.c:3962
foreign_expr_walker
static bool foreign_expr_walker(Node *node, foreign_glob_cxt *glob_cxt, foreign_loc_cxt *outer_cxt, foreign_loc_cxt *case_arg_cxt)
Definition: deparse.c:312
deparseColumnRef
static void deparseColumnRef(StringInfo buf, int varno, int varattno, RangeTblEntry *rte, bool qualify_col)
Definition: deparse.c:2712
deparseRelabelType
static void deparseRelabelType(RelabelType *node, deparse_expr_cxt *context)
Definition: deparse.c:3531
deparseNullTest
static void deparseNullTest(NullTest *node, deparse_expr_cxt *context)
Definition: deparse.c:3600
deparseOperatorName
static void deparseOperatorName(StringInfo buf, Form_pg_operator opform)
Definition: deparse.c:3440
deparseOpExpr
static void deparseOpExpr(OpExpr *node, deparse_expr_cxt *context)
Definition: deparse.c:3310
deparseConst
static void deparseConst(Const *node, deparse_expr_cxt *context, int showtype)
Definition: deparse.c:3054
isPlainForeignVar
static bool isPlainForeignVar(Expr *node, deparse_expr_cxt *context)
Definition: deparse.c:3405
deparseDistinctExpr
static void deparseDistinctExpr(DistinctExpr *node, deparse_expr_cxt *context)
Definition: deparse.c:3468
deparseSelectStmtForRel
void deparseSelectStmtForRel(StringInfo buf, PlannerInfo *root, RelOptInfo *rel, List *tlist, List *remote_conds, List *pathkeys, bool has_final_sort, bool has_limit, bool is_subquery, List **retrieved_attrs, List **params_list)
Definition: deparse.c:1266
deparseFuncExpr
static void deparseFuncExpr(FuncExpr *node, deparse_expr_cxt *context)
Definition: deparse.c:3247
deparseStringLiteral
void deparseStringLiteral(StringInfo buf, const char *val)
Definition: deparse.c:2880
rebuildInsertSql
void rebuildInsertSql(StringInfo buf, Relation rel, char *orig_query, List *target_attrs, int values_end_len, int num_params, int num_rows)
Definition: deparse.c:2187
foreign_glob_cxt
struct foreign_glob_cxt foreign_glob_cxt
deparseArrayExpr
static void deparseArrayExpr(ArrayExpr *node, deparse_expr_cxt *context)
Definition: deparse.c:3683
deparseInsertSql
void deparseInsertSql(StringInfo buf, RangeTblEntry *rte, Index rtindex, Relation rel, List *targetAttrs, bool doNothing, List *withCheckOptionList, List *returningList, List **retrieved_attrs, int *values_end_len)
Definition: deparse.c:2114
deparseReturningList
static void deparseReturningList(StringInfo buf, RangeTblEntry *rte, Index rtindex, Relation rel, bool trig_after_row, List *withCheckOptionList, List *returningList, List **retrieved_attrs)
Definition: deparse.c:2473
deparseUpdateSql
void deparseUpdateSql(StringInfo buf, RangeTblEntry *rte, Index rtindex, Relation rel, List *targetAttrs, List *withCheckOptionList, List *returningList, List **retrieved_attrs)
Definition: deparse.c:2247
deparseVar
static void deparseVar(Var *node, deparse_expr_cxt *context)
Definition: deparse.c:2983
appendFunctionName
static void appendFunctionName(Oid funcid, deparse_expr_cxt *context)
Definition: deparse.c:4084
appendConditions
static void appendConditions(List *exprs, deparse_expr_cxt *context)
Definition: deparse.c:1602
foreign_loc_cxt
struct foreign_loc_cxt foreign_loc_cxt
deparseDeleteSql
void deparseDeleteSql(StringInfo buf, RangeTblEntry *rte, Index rtindex, Relation rel, List *returningList, List **retrieved_attrs)
Definition: deparse.c:2393
deparseAnalyzeSql
void deparseAnalyzeSql(StringInfo buf, Relation rel, PgFdwSamplingMethod sample_method, double sample_frac, List **retrieved_attrs)
Definition: deparse.c:2592
deparseSubscriptingRef
static void deparseSubscriptingRef(SubscriptingRef *node, deparse_expr_cxt *context)
Definition: deparse.c:3201
deparseRelation
static void deparseRelation(StringInfo buf, Relation rel)
Definition: deparse.c:2840
deparseExplicitTargetList
static void deparseExplicitTargetList(List *tlist, bool is_returning, List **retrieved_attrs, deparse_expr_cxt *context)
Definition: deparse.c:1712
deparse_type_name
static char * deparse_type_name(Oid type_oid, int32 typemod)
Definition: deparse.c:1190
ADD_REL_QUALIFIER
#define ADD_REL_QUALIFIER(buf, varno)
Definition: deparse.c:111
appendLimitClause
static void appendLimitClause(deparse_expr_cxt *context)
Definition: deparse.c:4056
deparseExpr
static void deparseExpr(Expr *node, deparse_expr_cxt *context)
Definition: deparse.c:2915
is_foreign_expr
bool is_foreign_expr(PlannerInfo *root, RelOptInfo *baserel, Expr *expr)
Definition: deparse.c:244
deparseFromExprForRel
static void deparseFromExprForRel(StringInfo buf, PlannerInfo *root, RelOptInfo *foreignrel, bool use_alias, Index ignore_rel, List **ignore_conds, List **additional_conds, List **params_list)
Definition: deparse.c:1792
SUBQUERY_COL_ALIAS_PREFIX
#define SUBQUERY_COL_ALIAS_PREFIX
Definition: deparse.c:114
classifyConditions
void classifyConditions(PlannerInfo *root, RelOptInfo *baserel, List *input_conds, List **remote_conds, List **local_conds)
Definition: deparse.c:218
deparseScalarArrayOpExpr
static void deparseScalarArrayOpExpr(ScalarArrayOpExpr *node, deparse_expr_cxt *context)
Definition: deparse.c:3486
appendWhereClause
static void appendWhereClause(List *exprs, List *additional_conds, deparse_expr_cxt *context)
Definition: deparse.c:1639
deparseTruncateSql
void deparseTruncateSql(StringInfo buf, List *rels, DropBehavior behavior, bool restart_seqs)
Definition: deparse.c:2677
deparseSubqueryTargetList
static void deparseSubqueryTargetList(deparse_expr_cxt *context)
Definition: deparse.c:1748
is_foreign_pathkey
bool is_foreign_pathkey(PlannerInfo *root, RelOptInfo *baserel, PathKey *pathkey)
Definition: deparse.c:1156
deparseSelectSql
static void deparseSelectSql(List *tlist, bool is_subquery, List **retrieved_attrs, deparse_expr_cxt *context)
Definition: deparse.c:1348
deparseParam
static void deparseParam(Param *node, deparse_expr_cxt *context)
Definition: deparse.c:3168
build_tlist_to_deparse
List * build_tlist_to_deparse(RelOptInfo *foreignrel)
Definition: deparse.c:1209
appendAggOrderBy
static void appendAggOrderBy(List *orderList, List *targetList, deparse_expr_cxt *context)
Definition: deparse.c:3801
ERROR
#define ERROR
Definition: elog.h:39
elog
#define elog(elevel,...)
Definition: elog.h:226
equal
bool equal(const void *a, const void *b)
Definition: equalfuncs.c:223
OidOutputFunctionCall
char * OidOutputFunctionCall(Oid functionId, Datum val)
Definition: fmgr.c:1763
GetForeignTable
ForeignTable * GetForeignTable(Oid relid)
Definition: foreign.c:255
GetForeignColumnOptions
List * GetForeignColumnOptions(Oid relid, AttrNumber attnum)
Definition: foreign.c:293
format_type_extended
char * format_type_extended(Oid type_oid, int32 typemod, bits16 flags)
Definition: format_type.c:112
Assert
Assert(PointerIsAligned(start, uint64))
str
const char * str
Definition: hashfn_unstable.h:254
HeapTupleIsValid
#define HeapTupleIsValid(tuple)
Definition: htup.h:78
htup_details.h
GETSTRUCT
static void * GETSTRUCT(const HeapTupleData *tuple)
Definition: htup_details.h:728
val
long val
Definition: informix.c:689
b
int b
Definition: isn.c:74
a
int a
Definition: isn.c:73
i
int i
Definition: isn.c:77
if
if(TABLE==NULL||TABLE_index==NULL)
Definition: isn.c:81
lappend
List * lappend(List *list, void *datum)
Definition: list.c:339
list_concat
List * list_concat(List *list1, const List *list2)
Definition: list.c:561
lappend_int
List * lappend_int(List *list, int datum)
Definition: list.c:357
list_free
void list_free(List *list)
Definition: list.c:1546
list_free_deep
void list_free_deep(List *list)
Definition: list.c:1560
NoLock
#define NoLock
Definition: lockdefs.h:34
LCS_FORUPDATE
@ LCS_FORUPDATE
Definition: lockoptions.h:27
LCS_NONE
@ LCS_NONE
Definition: lockoptions.h:23
LCS_FORSHARE
@ LCS_FORSHARE
Definition: lockoptions.h:25
LCS_FORKEYSHARE
@ LCS_FORKEYSHARE
Definition: lockoptions.h:24
LCS_FORNOKEYUPDATE
@ LCS_FORNOKEYUPDATE
Definition: lockoptions.h:26
type_is_rowtype
bool type_is_rowtype(Oid typid)
Definition: lsyscache.c:2822
get_opfamily_member_for_cmptype
Oid get_opfamily_member_for_cmptype(Oid opfamily, Oid lefttype, Oid righttype, CompareType cmptype)
Definition: lsyscache.c:197
getTypeOutputInfo
void getTypeOutputInfo(Oid type, Oid *typOutput, bool *typIsVarlena)
Definition: lsyscache.c:3074
get_attname
char * get_attname(Oid relid, AttrNumber attnum, bool missing_ok)
Definition: lsyscache.c:920
get_namespace_name
char * get_namespace_name(Oid nspid)
Definition: lsyscache.c:3533
pfree
void pfree(void *pointer)
Definition: mcxt.c:1594
exprType
Oid exprType(const Node *expr)
Definition: nodeFuncs.c:42
exprIsLengthCoercion
bool exprIsLengthCoercion(const Node *expr, int32 *coercedTypmod)
Definition: nodeFuncs.c:557
strip_implicit_coercions
Node * strip_implicit_coercions(Node *node)
Definition: nodeFuncs.c:705
IsA
#define IsA(nodeptr, _type_)
Definition: nodes.h:164
nodeTag
#define nodeTag(nodeptr)
Definition: nodes.h:139
CMD_DELETE
@ CMD_DELETE
Definition: nodes.h:278
CMD_UPDATE
@ CMD_UPDATE
Definition: nodes.h:276
AGGSPLIT_SIMPLE
@ AGGSPLIT_SIMPLE
Definition: nodes.h:387
castNode
#define castNode(_type_, nodeptr)
Definition: nodes.h:182
JoinType
JoinType
Definition: nodes.h:298
JOIN_SEMI
@ JOIN_SEMI
Definition: nodes.h:317
JOIN_FULL
@ JOIN_FULL
Definition: nodes.h:305
JOIN_INNER
@ JOIN_INNER
Definition: nodes.h:303
JOIN_RIGHT
@ JOIN_RIGHT
Definition: nodes.h:306
JOIN_LEFT
@ JOIN_LEFT
Definition: nodes.h:304
PVC_RECURSE_PLACEHOLDERS
#define PVC_RECURSE_PLACEHOLDERS
Definition: optimizer.h:190
oprid
Oid oprid(Operator op)
Definition: parse_oper.c:239
DropBehavior
DropBehavior
Definition: parsenodes.h:2397
DROP_CASCADE
@ DROP_CASCADE
Definition: parsenodes.h:2399
DROP_RESTRICT
@ DROP_RESTRICT
Definition: parsenodes.h:2398
IS_SIMPLE_REL
#define IS_SIMPLE_REL(rel)
Definition: pathnodes.h:895
IS_JOIN_REL
#define IS_JOIN_REL(rel)
Definition: pathnodes.h:900
planner_rt_fetch
#define planner_rt_fetch(rti, root)
Definition: pathnodes.h:610
RELOPT_JOINREL
@ RELOPT_JOINREL
Definition: pathnodes.h:884
IS_UPPER_REL
#define IS_UPPER_REL(rel)
Definition: pathnodes.h:905
pg_aggregate.h
attname
NameData attname
Definition: pg_attribute.h:41
attnum
int16 attnum
Definition: pg_attribute.h:74
pg_authid.h
arg
void * arg
Definition: pg_backup_utils.c:29
relname
NameData relname
Definition: pg_class.h:38
pg_collation.h
while
while(p+4<=pend)
Definition: pg_crc32c_sse42.c:58
pg_database.h
lfirst
#define lfirst(lc)
Definition: pg_list.h:172
llast
#define llast(l)
Definition: pg_list.h:198
lfirst_node
#define lfirst_node(type, lc)
Definition: pg_list.h:176
list_length
static int list_length(const List *l)
Definition: pg_list.h:152
NIL
#define NIL
Definition: pg_list.h:68
forboth
#define forboth(cell1, list1, cell2, list2)
Definition: pg_list.h:518
lfirst_int
#define lfirst_int(lc)
Definition: pg_list.h:173
linitial
#define linitial(l)
Definition: pg_list.h:178
lsecond
#define lsecond(l)
Definition: pg_list.h:183
list_head
static ListCell * list_head(const List *l)
Definition: pg_list.h:128
lnext
static ListCell * lnext(const List *l, const ListCell *c)
Definition: pg_list.h:343
table
static const struct lconv_member_info table[]
Definition: pg_localeconv_r.c:63
pg_namespace.h
pg_operator.h
Form_pg_operator
FormData_pg_operator * Form_pg_operator
Definition: pg_operator.h:83
pg_opfamily.h
pg_proc.h
Form_pg_proc
FormData_pg_proc * Form_pg_proc
Definition: pg_proc.h:136
proname
NameData proname
Definition: pg_proc.h:35
options
static char ** options
Definition: pg_recvlogical.c:59
buf
static char * buf
Definition: pg_test_fsync.c:72
pg_ts_config.h
pg_ts_dict.h
pg_type.h
DatumGetObjectId
static Oid DatumGetObjectId(Datum X)
Definition: postgres.h:252
ObjectIdGetDatum
static Datum ObjectIdGetDatum(Oid X)
Definition: postgres.h:262
InvalidOid
#define InvalidOid
Definition: postgres_ext.h:37
Oid
unsigned int Oid
Definition: postgres_ext.h:32
reset_transmission_modes
void reset_transmission_modes(int nestlevel)
Definition: postgres_fdw.c:3929
set_transmission_modes
int set_transmission_modes(void)
Definition: postgres_fdw.c:3893
find_em_for_rel_target
EquivalenceMember * find_em_for_rel_target(PlannerInfo *root, EquivalenceClass *ec, RelOptInfo *rel)
Definition: postgres_fdw.c:7786
find_em_for_rel
EquivalenceMember * find_em_for_rel(PlannerInfo *root, EquivalenceClass *ec, RelOptInfo *rel)
Definition: postgres_fdw.c:7751
postgres_fdw.h
is_shippable
bool is_shippable(Oid objectId, Oid classId, PgFdwRelationInfo *fpinfo)
Definition: shippable.c:162
is_builtin
bool is_builtin(Oid objectId)
Definition: shippable.c:152
PgFdwSamplingMethod
PgFdwSamplingMethod
Definition: postgres_fdw.h:146
ANALYZE_SAMPLE_AUTO
@ ANALYZE_SAMPLE_AUTO
Definition: postgres_fdw.h:148
ANALYZE_SAMPLE_OFF
@ ANALYZE_SAMPLE_OFF
Definition: postgres_fdw.h:147
ANALYZE_SAMPLE_BERNOULLI
@ ANALYZE_SAMPLE_BERNOULLI
Definition: postgres_fdw.h:151
ANALYZE_SAMPLE_SYSTEM
@ ANALYZE_SAMPLE_SYSTEM
Definition: postgres_fdw.h:150
ANALYZE_SAMPLE_RANDOM
@ ANALYZE_SAMPLE_RANDOM
Definition: postgres_fdw.h:149
c
char * c
Definition: preproc-cursor.c:31
e
e
Definition: preproc-init.c:82
fe
static int fe(enum e x)
Definition: preproc-init.c:111
get_plan_rowmark
PlanRowMark * get_plan_rowmark(List *rowmarks, Index rtindex)
Definition: preptlist.c:526
AND_EXPR
@ AND_EXPR
Definition: primnodes.h:963
OR_EXPR
@ OR_EXPR
Definition: primnodes.h:963
NOT_EXPR
@ NOT_EXPR
Definition: primnodes.h:963
PARAM_MULTIEXPR
@ PARAM_MULTIEXPR
Definition: primnodes.h:387
IS_SPECIAL_VARNO
#define IS_SPECIAL_VARNO(varno)
Definition: primnodes.h:247
COERCE_IMPLICIT_CAST
@ COERCE_IMPLICIT_CAST
Definition: primnodes.h:768
COERCE_EXPLICIT_CAST
@ COERCE_EXPLICIT_CAST
Definition: primnodes.h:767
IS_NULL
@ IS_NULL
Definition: primnodes.h:1977
root
tree ctl root
Definition: radixtree.h:1857
RelationGetRelid
#define RelationGetRelid(relation)
Definition: rel.h:515
RelationGetDescr
#define RelationGetDescr(relation)
Definition: rel.h:541
RelationGetRelationName
#define RelationGetRelationName(relation)
Definition: rel.h:549
RelationGetNamespace
#define RelationGetNamespace(relation)
Definition: rel.h:556
quote_identifier
const char * quote_identifier(const char *ident)
Definition: ruleutils.c:13062
appendStringInfo
void appendStringInfo(StringInfo str, const char *fmt,...)
Definition: stringinfo.c:145
appendBinaryStringInfo
void appendBinaryStringInfo(StringInfo str, const void *data, int datalen)
Definition: stringinfo.c:281
appendStringInfoString
void appendStringInfoString(StringInfo str, const char *s)
Definition: stringinfo.c:230
appendStringInfoChar
void appendStringInfoChar(StringInfo str, char ch)
Definition: stringinfo.c:242
initStringInfo
void initStringInfo(StringInfo str)
Definition: stringinfo.c:97
Aggref::aggfnoid
Oid aggfnoid
Definition: primnodes.h:463
Aggref::aggdistinct
List * aggdistinct
Definition: primnodes.h:493
Aggref::aggdirectargs
List * aggdirectargs
Definition: primnodes.h:484
Aggref::args
List * args
Definition: primnodes.h:487
Aggref::aggfilter
Expr * aggfilter
Definition: primnodes.h:496
Aggref::aggorder
List * aggorder
Definition: primnodes.h:490
BoolExpr::boolop
BoolExprType boolop
Definition: primnodes.h:971
BoolExpr::args
List * args
Definition: primnodes.h:972
CaseExpr::arg
Expr * arg
Definition: primnodes.h:1346
CaseExpr::defresult
Expr * defresult
Definition: primnodes.h:1348
CaseExpr::args
List * args
Definition: primnodes.h:1347
CaseWhen::result
Expr * result
Definition: primnodes.h:1359
CaseWhen::expr
Expr * expr
Definition: primnodes.h:1358
CompactAttribute::attgenerated
bool attgenerated
Definition: tupdesc.h:78
Const::consttype
Oid consttype
Definition: primnodes.h:329
DefElem::defname
char * defname
Definition: parsenodes.h:843
FuncExpr::funcid
Oid funcid
Definition: primnodes.h:782
FuncExpr::args
List * args
Definition: primnodes.h:800
List
Definition: pg_list.h:54
Node
Definition: nodes.h:135
NullTest::nulltesttype
NullTestType nulltesttype
Definition: primnodes.h:1984
NullTest::arg
Expr * arg
Definition: primnodes.h:1983
OpExpr::opno
Oid opno
Definition: primnodes.h:850
OpExpr::args
List * args
Definition: primnodes.h:868
Param::paramtypmod
int32 paramtypmod
Definition: primnodes.h:399
Param::paramtype
Oid paramtype
Definition: primnodes.h:397
Param::paramkind
ParamKind paramkind
Definition: primnodes.h:395
Param::paramcollid
Oid paramcollid
Definition: primnodes.h:401
PathKey::pk_cmptype
CompareType pk_cmptype
Definition: pathnodes.h:1717
PathKey::pk_nulls_first
bool pk_nulls_first
Definition: pathnodes.h:1718
PathKey::pk_opfamily
Oid pk_opfamily
Definition: pathnodes.h:1716
PathTarget::exprs
List * exprs
Definition: pathnodes.h:1780
PgFdwRelationInfo::lower_subquery_rels
Relids lower_subquery_rels
Definition: postgres_fdw.h:120
PgFdwRelationInfo::outerrel
RelOptInfo * outerrel
Definition: postgres_fdw.h:103
PgFdwRelationInfo::attrs_used
Bitmapset * attrs_used
Definition: postgres_fdw.h:50
PgFdwRelationInfo::innerrel
RelOptInfo * innerrel
Definition: postgres_fdw.h:104
PlanRowMark::strength
LockClauseStrength strength
Definition: plannodes.h:1600
PlannerInfo::parse
Query * parse
Definition: pathnodes.h:227
Query::groupClause
List * groupClause
Definition: parsenodes.h:216
Query::groupingSets
List * groupingSets
Definition: parsenodes.h:220
RelOptInfo::relids
Relids relids
Definition: pathnodes.h:927
RelOptInfo::reltarget
struct PathTarget * reltarget
Definition: pathnodes.h:949
RelOptInfo::relid
Index relid
Definition: pathnodes.h:973
RelOptInfo::reloptkind
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Definition: pathnodes.h:921
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Definition: primnodes.h:1218
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Definition: primnodes.h:1217
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Definition: rel.h:117
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Definition: pathnodes.h:2792
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Definition: parsenodes.h:1469
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Definition: primnodes.h:725
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Definition: reltrigger.h:62
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Definition: reltrigger.h:57
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Definition: reltrigger.h:67
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Definition: primnodes.h:262
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Definition: primnodes.h:274
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Definition: primnodes.h:269
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Definition: deparse.c:99
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Definition: deparse.c:100
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Definition: deparse.c:106
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Definition: deparse.c:101
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Definition: deparse.c:105
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Definition: deparse.c:102
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Definition: deparse.c:68
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Definition: deparse.c:70
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Definition: deparse.c:71
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Definition: deparse.c:69
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Definition: deparse.c:90
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Definition: deparse.c:91
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Definition: deparse.c:92
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Definition: regguts.h:323
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Definition: sysattr.h:27
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Definition: sysattr.h:26
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Definition: sysattr.h:21
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Definition: syscache.c:264
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Definition: syscache.c:220
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Definition: table.c:126
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Definition: table.c:40
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Definition: tlist.c:132
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Definition: transam.h:197
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Definition: tupdesc.h:160
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Definition: tupdesc.h:175
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Definition: typcache.c:386
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Definition: typcache.h:140
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Definition: typcache.h:139
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Definition: var.c:653
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Definition: var.c:296