From: Noah Misch <noah@leadboat.com>
To: Peter Eisentraut <peter.eisentraut@2ndquadrant.com>
To: Tom Lane <tgl@sss.pgh.pa.us>
Cc: Robert Haas <robertmhaas@gmail.com>
Cc: pgsql-hackers <pgsql-hackers@postgresql.org>
Subject: Re: SQL-standard function body
Date: Sun, 18 Apr 2021 11:55:46 -0700
Message-ID: <20210418185546.GC1500781@rfd.leadboat.com> (raw)
In-Reply-To: <494838.1593543098@sss.pgh.pa.us>
References: <1c11f1eb-f00c-43b7-799d-2d44132c02d7@2ndquadrant.com>
<CA+TgmoZ-FXU0iyevFETN0sGYw0RKTSCFxKONGE+2nVJEM5_8OQ@mail.gmail.com>
<493812.1593541480@sss.pgh.pa.us>
<494838.1593543098@sss.pgh.pa.us>
On Tue, Jun 30, 2020 at 02:51:38PM -0400, Tom Lane wrote:
> The point remains that exposing the function body's dependencies will
> constrain restore order far more than we are accustomed to see. It
> might be possible to build examples that flat out can't be restored,
> even granting that we teach pg_dump how to break dependency loops
> by first creating the function with empty body and later redefining
> it with the real body. (Admittedly, if that's possible then you
> likely could make it happen with views too. But somehow it seems
> more likely that people would create spaghetti dependencies for
> functions than views.)
Should we be okay releasing v14 without support for breaking function
dependency loops, or does that call for an open item?
-- example
create function f() returns int language sql return 1;
create function g() returns int language sql return f();
create or replace function f() returns int language sql return coalesce(2, g());
-- but when a view can break the cycle, pg_dump still does so
create view v as select 1 as c;
create function f() returns int language sql return coalesce(0, (select count(*) from v));
create or replace view v as select f() as c;
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To: pgsql-hackers@postgresql.org
Cc: noah@leadboat.com, peter.eisentraut@2ndquadrant.com, tgl@sss.pgh.pa.us, robertmhaas@gmail.com
Subject: Re: SQL-standard function body
In-Reply-To: <20210418185546.GC1500781@rfd.leadboat.com>
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