How Postgres achieves database-level isolation

Question

Per doc of postgres,

Databases are physically separated and access control is managed at the connection level.

Is there any further details that how Postgres achieves this physical isolation? Are those files used to store data in the backend totally separate?

Craig Ringer · Accepted Answer · 2017-09-11 02:11:14Z

1

Is there any further details that how postgres archives this physical isolation? Are those files used to store data in the backend totally separate?

Yes. Each table is stored as a separate file (actually, multiple files). Different databases are in different directories. Indexes, etc are also in one or more separate files.

However, there's a lot of shared state. Some system tables are shared between all databases. The write-ahead log (WAL) is also shared, as is the commit log (pg_clog). So you cannot just extract one database's files and attach it to another PostgreSQL instance. They're meaningless without some of the shared files.

answered Sep 11, 2017 at 2:11

Craig Ringer

329k83 gold badges742 silver badges820 bronze badges

Sign up to request clarification or add additional context in comments.

Collectives™ on Stack Overflow

How Postgres achieves database-level isolation

1 Answer 1

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

Comments

Your Answer

Sign up or log in

Post as a guest

Related