From: Tom Lane <tgl@sss.pgh.pa.us>
To: Nathan Bossart <nathandbossart@gmail.com>
cc: Peter Geoghegan <pg@bowt.ie>, postgresql@taljaren.se,
        pgsql-hackers@lists.postgresql.org,
        Michael Paquier <michael@paquier.xyz>
Subject: Re: BUG #17717: Regression in vacuumdb (15 is slower than 10/11 and
 possible memory issue)
In-reply-to: <20221228212150.GA4009813@nathanxps13>
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Comments: In-reply-to Nathan Bossart <nathandbossart@gmail.com>
	message dated "Wed, 28 Dec 2022 13:21:50 -0800"
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Date: Wed, 28 Dec 2022 17:05:39 -0500
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Nathan Bossart <nathandbossart@gmail.com> writes:
> On Wed, Dec 28, 2022 at 03:13:23PM -0500, Tom Lane wrote:
>> +		executeCommand(conn, "VACUUM (ONLY_DATABASE_STATS);", echo);

> When I looked at this, I thought it would be better to send the command
> through the parallel slot machinery so that failures would use the same
> code path as the rest of the VACUUM commands.  However, you also need to
> adjust ParallelSlotsWaitCompletion() to mark the slots as idle so that the
> slot array can be reused after it is called.

Hm.  I was just copying the way commands are issued further up in the
same function.  But I think you're right: once we've done

	ParallelSlotsAdoptConn(sa, conn);

it's probably not entirely kosher to use the conn directly.

			regards, tom lane