From: Andy Fan <zhihuifan1213@163.com>
To: Tom Lane <tgl@sss.pgh.pa.us>
Cc: "pgsql-hackers@lists.postgresql.org" <pgsql-hackers@lists.postgresql.org>
Subject: Re: Why does exec_simple_query requires 2 snapshots
In-Reply-To: <1241667.1739893420@sss.pgh.pa.us> (Tom Lane's message of "Tue,
	18 Feb 2025 10:43:40 -0500")
References: <87o6yzbhip.fsf@163.com> <1241667.1739893420@sss.pgh.pa.us>
Date: Wed, 19 Feb 2025 01:10:21 +0000
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Tom Lane <tgl@sss.pgh.pa.us> writes:

> Andy Fan <zhihuifan1213@163.com> writes:
>> My question is why can't we share the same snapshot for the 2 cases?
>> parser & planner requires Catalog Snapshot which should be the 
>> latest one, but in the above case, looks the executor can reuse it as
>> well. Is there anything I missed?
>
> Many years ago, we committed a patch to do exactly that.  We had
> to back it out again because it broke too many real-world scenarios.
> I'm too lazy to search the archives for you, but you might be able
> to find the commit and revert by searching the git history.
>
> 			regards, tom lane

Commit id is 532994299e2, thank you Tom!

-- 
Best Regards
Andy Fan