From fd48a86c6241b994ce67c8b53a918e6b42c8063c Mon Sep 17 00:00:00 2001 From: Masahiko Sawada Date: Thu, 13 Jul 2023 15:03:17 +0900 Subject: Doc: clarify the conditions of usable indexes for REPLICA IDENTITY FULL tables. 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 --- doc/src/sgml/logical-replication.sgml | 12 ++++++------ 1 file changed, 6 insertions(+), 6 deletions(-) (limited to 'doc/src') diff --git a/doc/src/sgml/logical-replication.sgml b/doc/src/sgml/logical-replication.sgml index c5de2040f78..c2a749d8828 100644 --- a/doc/src/sgml/logical-replication.sgml +++ b/doc/src/sgml/logical-replication.sgml @@ -134,12 +134,12 @@ to replica identity FULL, which means the entire row becomes the key. When replica identity FULL 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 FULL 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 FULL should only be used as a fallback if no other solution is possible. If a replica identity other than FULL is set on the publisher side, a replica identity comprising the same or fewer columns must also be set on the subscriber -- cgit v1.2.3