2015-12-12 19:00 GMT+01:00 Simon Slavin <slavins at bigfraud.org>: > > On 12 Dec 2015, at 2:42pm, Cecil Westerhof <cldwesterhof at gmail.com> wrote: > > >> SELECT > >> (SELECT COUNT(*) FROM proverbs) AS Total > >> , (SELECT COUNT(*) FROM proverbs WHERE used IS NOT NULL) AS Used > >> , (SELECT COUNT(*) FROM proverbs WHERE used IS NULL) AS Free > >> > > > > ?That is what I am using now, but it is inefficient. This uses three > scans > > instead of two.? > > Do you have an index on the column 'used' ?
?Not at the moment. But maybe that is a good idea.? -- Cecil Westerhof