Re: integrate pg_upgrade analyze_new_cluster.sh into vacuumdb

From: Simon Riggs <simon(at)2ndQuadrant(dot)com>
To: Peter Eisentraut <peter_e(at)gmx(dot)net>
Cc: pgsql-hackers <pgsql-hackers(at)postgresql(dot)org>
Subject: Re: integrate pg_upgrade analyze_new_cluster.sh into vacuumdb
Date: 2014-04-13 12:13:16
Message-ID: CA+U5nMJZ+x=yRAEUMPu4m=TSoAF7yWLNAKZ-Xvz7EqH+PJhTxA@mail.gmail.com
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On 4 April 2014 16:01, Andres Freund <andres(at)2ndquadrant(dot)com> wrote:

>> + const char *stage_commands[] = {
>> + "SET default_statistics_target=1; SET vacuum_cost_delay=0;",
>> + "SET default_statistics_target=10; RESET vacuum_cost_delay;",
>> + "RESET default_statistics_target;"

> This whole thing won't work for relations with per-column statistics
> targets btw...

Yes, agreed. Plus I would note that this makes no difference at all
for very small tables since the sample will be big enough even with
stats_target=1.

ISTM that this is the way ANALYZE should work when run on a table that
has never been analysed before. Let's just do this logic within
ANALYZE and be done.

Suggest logic
if not ANALYZEd before && table is not small && stats_target is
default then AnalyzeInStages()
otherwise just do one ANALYZE pass

--
Simon Riggs http://www.2ndQuadrant.com/
PostgreSQL Development, 24x7 Support, Training & Services

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