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| To: | pgsql-docs(at)lists(dot)postgresql(dot)org |
| Cc: | eric(dot)mutta(at)gmail(dot)com |
| Subject: | Should 'sum(mvf)' read 'sum(mcv)'...? |
| Date: | 2022-08-21 23:02:04 |
| Message-ID: | 166112292492.654.5377188452604176150@wrigleys.postgresql.org |
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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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