Message-ID: <05c08a663f357eecae09942b3939e560bcb0fc18.camel@gmail.com>
Subject: Re: CREATE INDEX CONCURRENTLY on partitioned index
From: Ilya Gladyshev <ilya.v.gladyshev@gmail.com>
To: Justin Pryzby <pryzby@telsasoft.com>
Cc: Alexander Pyhalov <a.pyhalov@postgrespro.ru>,
 pgsql-hackers@lists.postgresql.org, Masahiko Sawada
 <sawada.mshk@gmail.com>,  Michael Paquier <michael@paquier.xyz>,
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 <adger.lj@alibaba-inc.com>,
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 <wenjing.zwj@alibaba-inc.com>, Alvaro Herrera <alvherre@2ndquadrant.com>
Date: Fri, 09 Dec 2022 17:53:10 +0400
In-Reply-To: <20221204190935.GD14156@telsasoft.com>
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On Sun, 2022-12-04 at 13:09 -0600, Justin Pryzby wrote:
> 
> This beavior is fixed.  I re-factored and re-implented to use
> DefineIndex() for building indexes concurrently rather than
> reindexing.
> That makes the patch smaller, actually, and has the added benefit of
> splitting off the "Concurrently" part of DefineIndex() into a
> separate
> function.

Nice, I think it turned out pretty concise. I played around with the
patch quite a bit, didn't find any major problems, the only minor thing
that I can note is that we should skip the top parent index itself in
the loop not to increment the pg_stat counter, something like this:

diff --git a/src/backend/commands/indexcmds.c
b/src/backend/commands/indexcmds.c
index cfab45b999..9049540b5b 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -1515,6 +1515,9 @@ DefineIndex(Oid relationId,
                        Oid                     indrelid =
lfirst_oid(lc);
                        Oid                     tabrelid =
IndexGetRelation(indrelid, false);
 
+                       if (indrelid == indexRelationId)
+                               continue;
+
                        if
(RELKIND_HAS_STORAGE(get_rel_relkind(indrelid)) &&
                                !get_index_isvalid(indrelid))
                        {
> 
> BTW, it causes the patch to fail to apply in cfbot when you send an
> additional (002) supplementary patch without including the original
> (001) patch.  You can name it *.txt to avoid the issue.
>  
> https://wiki.postgresql.org/wiki/Cfbot#Which_attachments_are_considered_to_be_patches.3F
> 
> Thanks for looking.
> 
My bad, didn't know about this, thanks for the link.

On a side note, I noticed that reindex behaviour is strange on
partitioned tables, it doesn't mark partitioned tables as valid after
reindexing children, as I could understand from the code and mailing
lists, this is the intended behaviour, but I can't quite understand the
rationale for it, do you know why it is done this way?