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Re: Column Filtering in Logical Replication

Tomas Vondra <tomas.vondra@enterprisedb.com>

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From: Tomas Vondra <tomas.vondra@enterprisedb.com>
To: Amit Kapila <amit.kapila16@gmail.com>
Cc: "houzj.fnst@fujitsu.com" <houzj.fnst@fujitsu.com>, Peter Eisentraut <peter.eisentraut@enterprisedb.com>, Alvaro Herrera <alvherre@alvh.no-ip.org>, Justin Pryzby <pryzby@telsasoft.com>, Rahila Syed <rahilasyed90@gmail.com>, Peter Smith <smithpb2250@gmail.com>, pgsql-hackers <pgsql-hackers@postgresql.org>, "shiy.fnst@fujitsu.com" <shiy.fnst@fujitsu.com>
Date: 2022-03-30T12:01:38Z
Lists: pgsql-hackers 

On 3/30/22 04:46, Amit Kapila wrote:
> On Tue, Mar 29, 2022 at 6:09 PM Tomas Vondra
> <tomas.vondra@enterprisedb.com> wrote:
>>
>> On 3/29/22 13:47, Amit Kapila wrote:
>>> On Tue, Mar 29, 2022 at 4:33 PM Tomas Vondra
>>> <tomas.vondra@enterprisedb.com> wrote:
>>>>
>>>> On 3/29/22 12:00, Amit Kapila wrote:
>>>>>>
>>>>>> Thanks, I'll take a look later.
>>>>>>
>>>>>
>>>>> This is still failing [1][2].
>>>>>
>>>>> [1] - https://buildfarm.postgresql.org/cgi-bin/show_log.pl?nm=florican&dt=2022-03-28%2005%3A16%3A53
>>>>> [2] - https://buildfarm.postgresql.org/cgi-bin/show_log.pl?nm=flaviventris&dt=2022-03-24%2013%3A13%3A08
>>>>>
>>>>
>>>> AFAICS we've concluded this is a pre-existing issue, not something
>>>> introduced by a recently committed patch, and I don't think there's any
>>>> proposal how to fix that.
>>>>
>>>
>>> I have suggested in email [1] that increasing values
>>> max_sync_workers_per_subscription/max_logical_replication_workers
>>> should solve this issue. Now, whether this is a previous issue or
>>> behavior can be debatable but I think it happens for the new test case
>>> added by commit c91f71b9dc.
>>>
>>
>> IMHO that'd be just hiding the actual issue, which is the failure to
>> sync the subscription in some circumstances. We should fix that, not
>> just make sure the tests don't trigger it.
>>
> 
> I am in favor of fixing/changing some existing behavior to make it
> better and would be ready to help in that investigation as well but
> was just not sure if it is a good idea to let some of the buildfarm
> member(s) fail for a number of days. Anyway, I leave this judgment to
> you.
> 

OK. If it affected more animals, and/or if they were failing more often,
it'd definitely warrant a more active approach. But AFAICS it affects
only a tiny fraction, and even there it fails maybe 1 in 20 runs ...

Plus the symptoms are pretty clear, it's unlikely to cause enigmatic
failures, forcing people to spend time on investigating it.

Of course, that's my assessment and it feels weird as it goes directly
against my instincts to keep all tests working :-/


regards

-- 
Tomas Vondra
EnterpriseDB: http://www.enterprisedb.com
The Enterprise PostgreSQL Company

Commits

Same data as JSON: GET /api/v1/messages/:b64id/commits the thread's linked commits as JSON, with link sources. API reference →

  1. Doc: Explain about Column List feature.

  2. Doc: fix column list vs. replica identity rules.

  3. Prohibit combining publications with different column lists.

  4. Fix the check to limit sync workers.

  5. Wait for subscription to sync in t/031_column_list.sql

  6. Move prattrs to the pg_publication_rel section in docs

  7. Allow specifying column lists for logical replication

  8. Fix row filters with multiple publications

  9. Fix publish_as_relid with multiple publications

  10. Add some additional tests for row filters in logical replication.

  11. Add index on pg_publication_rel.prpubid

  12. Avoid using DefElemAction in AlterPublicationStmt

  13. Small cleanups related to PUBLICATION framework code

  14. Add PublicationTable and PublicationRelInfo structs

  15. Fix various concurrency issues in logical replication worker launching