From: PG Doc comments form <noreply@postgresql.org>
To: pgsql-docs@lists.postgresql.org
Cc: eric.mutta@gmail.com
Subject: Should 'sum(mvf)' read 'sum(mcv)'...?
Date: Sun, 21 Aug 2022 23:02:04 +0000
Message-ID: <166112292492.654.5377188452604176150@wrigleys.postgresql.org> (raw)
The following documentation comment has been logged on the website:
Page: https://www.postgresql.org/docs/14/row-estimation-examples.html
Description:
About halfway down this page
https://www.postgresql.org/docs/current/row-estimation-examples.html we see
the following formula for calculating selectivity:
> selectivity = (1 - sum(mvf))/(num_distinct - num_mcv)
And just below the formula we see the explanatory sentence saying:
> That is, add up all the frequencies for the MCVs and subtract them from
one, ...
It appears the above sentence is referring to the "(1 - sum(mvf))" portion
of the formula, however I am not sure what "mvf" is referring to
there...shouldn't it be "(1 - sum(mcv))" in order to match what the
explanatory sentence is saying?
Many thanks,
Eric Mutta.
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Subject: Re: Should 'sum(mvf)' read 'sum(mcv)'...?
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