Hi, On Sun, Aug 21, 2022 at 11:02:04PM +0000, PG Doc comments form wrote: > 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?
It should be mcf, ie. Most Common Frequencies. It looks like a very old typo that survived until now.
