From: Justin Pryzby <pryzby@telsasoft.com>
To: Rick Otten <rottenwindfish@gmail.com>
Cc: Tom Lane <tgl@sss.pgh.pa.us>
Cc: PostgreSQL mailing lists <pgsql-performance@postgresql.org>
Subject: Re: failing to use index on UNION of matviews (Re: postgresql 10.1 wrong plan in when using partitions bug)
Date: Tue, 6 Feb 2018 12:18:07 -0600
Message-ID: <20180206181807.GC32634@telsasoft.com> (raw)
In-Reply-To: <CAMAYy4JzsBvX+LPunq3Pq0+gyBo31x1HyRD+DiJxjwweAtzSbw@mail.gmail.com>
References: <CA+t6e1m54jrEj7spf9ArH5BJiO-Qznn=_YCRGWWMtohvXg7mEg@mail.gmail.com>
<CAMAYy4KT-xvP6Q7iBvW5YAmmcrzpyTfACaLdjKn_tTvLNUu9+w@mail.gmail.com>
<15450.1517758532@sss.pgh.pa.us>
<CAMAYy4JzsBvX+LPunq3Pq0+gyBo31x1HyRD+DiJxjwweAtzSbw@mail.gmail.com>
On Sun, Feb 04, 2018 at 11:04:56AM -0500, Rick Otten wrote:
> On Sun, Feb 4, 2018 at 10:35 AM, Tom Lane <tgl@sss.pgh.pa.us> wrote:
>
> > Rick Otten <rottenwindfish@gmail.com> writes:
> > > I'm wrestling with a very similar problem too - except instead of
> > official
> > > partitions I have a views on top of a bunch (50+) of unioned materialized
> > > views, each "partition" with 10M - 100M rows. On 9.6.6 the queries would
> > > use the indexes on each materialized view. On 10.1, every materialized
> > > view is sequence scanned.
I think it'd be useful to see the plan from explain analyze, on both the
"parent" view and a child, with and without SET enable_seqscan=off,
Justin
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To: pgsql-performance@postgresql.org
Cc: pryzby@telsasoft.com, rottenwindfish@gmail.com, tgl@sss.pgh.pa.us
Subject: Re: failing to use index on UNION of matviews (Re: postgresql 10.1 wrong plan in when using partitions bug)
In-Reply-To: <20180206181807.GC32634@telsasoft.com>
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