From: Tom Lane <tgl@sss.pgh.pa.us>
To: Alexander Pyhalov <a.pyhalov@postgrespro.ru>
cc: Pavel Stehule <pavel.stehule@gmail.com>,
        Alexander Korotkov <aekorotkov@gmail.com>,
        pgsql-hackers@lists.postgresql.org,
        Ronan Dunklau <ronan.dunklau@aiven.io>
Subject: Re: SQLFunctionCache and generic plans
In-reply-to: <db42573039cc66815e80a48589eebea8@postgrespro.ru>
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Comments: In-reply-to Alexander Pyhalov <a.pyhalov@postgrespro.ru>
	message dated "Sat, 29 Mar 2025 10:24:41 +0300"
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Date: Sat, 29 Mar 2025 10:08:49 -0400
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Alexander Pyhalov <a.pyhalov@postgrespro.ru> writes:
> After writing some comments, looking at it once again, I've found that 
> one assumption is wrong - function can be discarded from cache during 
> its execution.

Yeah.  You really need a use-count on the shared cache object.

I've been working on pulling out plpgsql's code that manages its
function cache into a new module that can be shared with functions.c.
That code is quite battle-tested and I don't see a good argument
for reinventing the logic.  It's not fit to share yet, but I hope
to have something in a day or so.

> Also one interesting note is as we don't use raw_parse_tree, it seems we 
> don't need plansource->parserSetup and plansource->parserSetupArg. It 
> seems we can avoid caching complete parse info.

Well, you do need those when dealing with an old-style function (raw
parse trees).

			regards, tom lane