From: Tom Lane <tgl@sss.pgh.pa.us>
To: Alvaro Herrera <alvherre@2ndquadrant.com>
cc: Peter Geoghegan <pg@bowt.ie>,
        hubert depesz lubaczewski <depesz@depesz.com>,
        pgsql-bugs mailing list <pgsql-bugs@postgresql.org>,
        Peter Eisentraut <peter.eisentraut@2ndquadrant.com>
Subject: Re: gen_random_uuid() is immutable in Pg 13devel
In-reply-to: <20200218200122.GA7247@alvherre.pgsql>
References: <20200218200122.GA7247@alvherre.pgsql>
Comments: In-reply-to Alvaro Herrera <alvherre@2ndquadrant.com>
	message dated "Tue, 18 Feb 2020 17:01:22 -0300"
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Date: Tue, 18 Feb 2020 17:58:03 -0500
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Alvaro Herrera <alvherre@2ndquadrant.com> writes:
> On 2020-Feb-18, Peter Geoghegan wrote:
>> Maybe this happened because the default volatility for pg_proc.dat
>> entries is not 'volatile' -- it's 'immutable'.

> That makes me wonder what should be the default --- and should there
> even *be* a default in the first place?  Maybe it's better to make
> everyone *think* about it every time rather than hoping we'll all
> remember, and frequently having it got wrong.

Yeah.  That default was chosen just to reduce the size of pg_proc.dat
(since a large majority of C functions are indeed immutable).  But
it might be too error-prone this way.  I remember worrying about that
when we put it in.

			regards, tom lane