From: Tom Lane <tgl@sss.pgh.pa.us>
To: Jeff Davis <pgsql@j-davis.com>
cc: Ashutosh Bapat <ashutosh.bapat.oss@gmail.com>,
        pgsql-hackers <pgsql-hackers@postgresql.org>,
        Corey Huinker <corey.huinker@gmail.com>
Subject: Re: Statistics import and export: difference in statistics of
 materialized view dumped
In-reply-to: <a443f2322c61ab38d6b3ac3915fe0afaf0235b93.camel@j-davis.com>
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 <1427602.1741702648@sss.pgh.pa.us>
 <a443f2322c61ab38d6b3ac3915fe0afaf0235b93.camel@j-davis.com>
Comments: In-reply-to Jeff Davis <pgsql@j-davis.com>
	message dated "Tue, 11 Mar 2025 08:21:43 -0700"
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Date: Tue, 11 Mar 2025 11:26:44 -0400
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Jeff Davis <pgsql@j-davis.com> writes:
> On Tue, 2025-03-11 at 10:17 -0400, Tom Lane wrote:
>> Are you doing the restore in parallel by any chance?  I had a todo
>> item to revisit the dependencies that pg_dump is creating for stats
>> items, because they looked wrong to me, ie inadequate to guarantee
>> correct restore order.

> It's creating a dependency on the relation and a boundary dependency on
> the postDataBound (unless it's an index, or an MV that got pushed to
> SECTION_POST_DATA).
> I suspect what we need here is a dependency on the MV *data*, because
> that's doing a heap swap, which resets the stats. Looking into it.

Right, that was what I was thinking, but hadn't had time to look in
detail.  The postDataBound dependency isn't real helpful here, we
could lose that if we had the data dependency.

			regards, tom lane