Horton

Re: [PATCH] Use indexes on the subscriber when REPLICA IDENTITY is full on the publisher

Önder Kalacı <onderkalaci@gmail.com>

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From: Önder Kalacı <onderkalaci@gmail.com>
To: Andres Freund <andres@anarazel.de>
Cc: Amit Kapila <amit.kapila16@gmail.com>, "shiy.fnst@fujitsu.com" <shiy.fnst@fujitsu.com>, Marco Slot <marco.slot@gmail.com>, Tom Lane <tgl@sss.pgh.pa.us>, "wangw.fnst@fujitsu.com" <wangw.fnst@fujitsu.com>, PostgreSQL Hackers <pgsql-hackers@lists.postgresql.org>
Date: 2023-03-07T10:59:08Z
Lists: pgsql-hackers 
Hi Andres, Amit, all

I think the case in which the patch regresses performance in is irrelevant
> in
> practice.
>

This is similar to what I think in this context.

I appreciate the effort from Shi Yu, so that we have a clear understanding
on the overhead.
But the tests we do on [1] where we observe the regression are largely
synthetic test cases
that aim to spot the overhead.

And having an index over thousands
> of non-differing values will generally perform badly, not just in this
> context.


Similarly, maybe there are some eccentric use patterns that might follow
this. But I also suspect
even if there are such patterns, could they really be performance sensitive?


Thanks,
Onder KALACI

[1]
https://www.postgresql.org/message-id/OSZPR01MB63103A4AFBBA56BAF8AE7FAAFDA39%40OSZPR01MB6310.jpnprd01.prod.outlook.com

Commits

  1. Add the testcases for 89e46da5e5.

  2. Allow the use of indexes other than PK and REPLICA IDENTITY on the subscriber.

  3. Rework query relation permission checking

  4. Generalize ri_RootToPartitionMap to use for non-partition children

  5. Add wait_for_subscription_sync for TAP tests.

  6. Logical replication