database/postgres
1
0
Fork 0
mirror of https://github.com/postgres/postgres.git synced 2025-06-13 07:41:39 +03:00
Code Activity

Doc: clarify the conditions of usable indexes for REPLICA IDENTITY FULL tables.

Browse Source 
Commit 89e46da5e allowed REPLICA IDENTITY FULL tables to use an index
on the subscriber during apply of update/delete. This commit clarifies
in the documentation that the leftmost field of candidate indexes must
be a column (not an expression) that references the published relation
column.

The source code comments are also updated accordingly.

Reviewed-by: Peter Smith, Amit Kapila
Discussion: https://postgr.es/m/CAD21AoDJjffEvUFKXT27Q5U8-UU9JHv4rrJ9Ke8Zkc5UPWHLvA@mail.gmail.com
Backpatch-through: 16
This commit is contained in:
Masahiko Sawada
2023-07-13 15:03:17 +09:00
parent 0fef877538
commit fd48a86c62
3 changed files with 13 additions and 16 deletions
Download Patch File Download Diff File Expand all files Collapse all files

12
doc/src/sgml/logical-replication.sgml
View File

@ -134,12 +134,12 @@
to replica identity <literal>FULL</literal>, which means the entire row becomes
the key. When replica identity <literal>FULL</literal> is specified,
indexes can be used on the subscriber side for searching the rows. Candidate
indexes must be btree, non-partial, and have at least one column reference
(i.e. cannot consist of only expressions). These restrictions
on the non-unique index properties adhere to some of the restrictions that
are enforced for primary keys. If there are no such suitable indexes,
the search on the subscriber side can be very inefficient, therefore
replica identity <literal>FULL</literal> should only be used as a
indexes must be btree, non-partial, and the leftmost index field must be a
column (not an expression) that references the published table column. These
restrictions on the non-unique index properties adhere to some of the
restrictions that are enforced for primary keys. If there are no such
suitable indexes, the search on the subscriber side can be very inefficient,
therefore replica identity <literal>FULL</literal> should only be used as a
fallback if no other solution is possible. If a replica identity other
than <literal>FULL</literal> is set on the publisher side, a replica identity
comprising the same or fewer columns must also be set on the subscriber