Date: Fri, 6 Dec 2019 12:04:45 +0900
From: Michael Paquier <michael@paquier.xyz>
To: James Salsman <jsalsman@gmail.com>
Cc: pgsql-docs@lists.postgresql.org
Subject: Re: monitoring-stats.html is too impenetrable
Message-ID: <20191206030445.GI121835@paquier.xyz>
References: <157458791863.7229.15011272113637426410@wrigleys.postgresql.org>
 <20191125012036.GC37821@paquier.xyz>
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On Wed, Dec 04, 2019 at 03:29:55AM -0800, James Salsman wrote:
> Thank you for your thoughtful reply. This might be much easier:
>=20
> How about adding another example to
> https://www.postgresql.org/docs/11/planner-stats.html ?

Not sure I see the parallel here.  This page talks about planner
statistics, and yours about being able to find missing indexes because
of incorrect stats.

> SELECT relname, seq_scan-idx_scan AS too_much_seq,
>    case when seq_scan-idx_scan>0 THEN 'Missing Index?' ELSE 'OK' END,
>    pg_relation_size(relid::regclass) AS rel_size, seq_scan, idx_scan
> FROM pg_stat_all_tables
> WHERE schemaname=3D'public' AND pg_relation_size(relid::regclass)>80000
> ORDER BY too_much_seq DESC;

Again.  this is a bit more complex than that.
--
Michael

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