From: Tom Lane <tgl@sss.pgh.pa.us>
To: Kevin Grittner <kgrittn@gmail.com>
cc: pgsql-hackers@postgreSQL.org
Subject: How huge does mvtest_huge need to be?
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Date: Wed, 03 May 2017 13:08:40 -0400
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Continuing to investigate possible speedups of the regression tests,
I noticed that some of the slower individual statements are those
dealing with mvtest_huge and mvtest_hugeview in matview.sql.
Cutting the size of mvtest_huge from 100K rows to 10K rows is enough
to halve the overall runtime of matview.sql, at least on the relatively
slow buildfarm animal I was checking this on.

I was going to propose doing that, but then looking at commit b69ec7cc9
which introduced these tables, I began to wonder why they're large at all.
Even a one-row matview would have been enough to test for the bug that
that commit fixed.

So ... is there a good reason to be using a large table here, and
if so what is it, and how big does the table really need to be
to provide useful test coverage?

			regards, tom lane


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