From: Tom Lane <tgl@sss.pgh.pa.us>
To: y.saburov@gmail.com
Cc: pgsql-docs@lists.postgresql.org
Subject: Re: The examples given in Chapter 14 are not true.
Date: Sun, 26 May 2024 10:35:34 -0400
Message-ID: <2752.1716734134@sss.pgh.pa.us> (raw)
In-Reply-To: <171673189739.2021727.14284698255790538307@wrigleys.postgresql.org>
References: <171673189739.2021727.14284698255790538307@wrigleys.postgresql.org>
PG Doc comments form <noreply@postgresql.org> writes:
> Page: https://www.postgresql.org/docs/16/performance-tips.html> 1) How did you create the `tenk1` table?
As the text says, it's supposed to be made by running the core
regression tests ("make installcheck").
> 1) relpages for table `tenk1` - different in version 16. Some calculations
> will be incorrect accordingly
> 2) you will not be able to reproduce examples for which there are no indexes
> in table `tenk1` - for example index `index_tenk1_on_four`.
Yeah, that's a bit out of date. I fixed it up awhile ago for v17:
https://git.postgresql.org/gitweb/?p=postgresql.git&a=commitdiff&h=5caa05749
However, the text also points out that you won't necessarily get
exactly the same results as are shown, for assorted reasons of
which different-version is only one. So I think these changes
were more neatnik-ism than rescuing the chapter from total
irrelevancy.
regards, tom lane
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Subject: Re: The examples given in Chapter 14 are not true.
In-Reply-To: <2752.1716734134@sss.pgh.pa.us>
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