From: Alvaro Herrera <alvherre@2ndquadrant.com>
To: Andrew Dunstan <andrew@dunslane.net>
Cc: Tom Lane <tgl@sss.pgh.pa.us>
Cc: Peter Geoghegan <pg@heroku.com>
Cc: Jim Nasby <Jim.Nasby@bluetreble.com>
Cc: Pg Hackers <pgsql-hackers@postgresql.org>
Subject: Re: Less than ideal error reporting in pg_stat_statements
Date: Mon, 5 Oct 2015 12:40:32 -0300
Message-ID: <20151005154032.GF8531@alvherre.pgsql> (raw)
In-Reply-To: <561296EC.805@dunslane.net>
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Andrew Dunstan wrote:
>
> On 10/05/2015 11:15 AM, Tom Lane wrote:
> >Peter Geoghegan <pg@heroku.com> writes:
> >>I'm annoyed and disappointed that the patch committed does not even
> >>begin to address the underlying problem -- it just adds an escape
> >>hatch, and fixes another theoretical issue that no one was affected
> >>by. Honestly, next time I won't bother.
> >The problem as I see it is that what you submitted is a kluge that will
> >have weird and unpredictable side effects. Moreover, it seems to be
> >targeting an extremely narrow problem case, ie large numbers of queries
> >that (a) have long query texts and (b) are distinct to the fingerprinting
> >code and (c) fail. It seems to me that you could get into equal trouble
> >with situations where (c) is not satisfied, and what then?
> FWIW, (a) and (b) but not (c) is probably the right description for my
> client who has been seeing problems here.
I think the fact that long IN lists are fingerprinted differently
according to the number of elements in the list makes the scenario
rather very likely -- not particularly narrow.
--
Álvaro Herrera http://www.2ndQuadrant.com/
PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services
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Cc: alvherre@2ndquadrant.com, andrew@dunslane.net, tgl@sss.pgh.pa.us, pg@heroku.com, Jim.Nasby@bluetreble.com
Subject: Re: Less than ideal error reporting in pg_stat_statements
In-Reply-To: <20151005154032.GF8531@alvherre.pgsql>
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