Re: NOT LIKE much faster than LIKE?

Andrea Arcangeli <andrea(at)cpushare(dot)com> writes:

> Fixing this with proper stats would be great indeed. What would be the
> most common value for the kernel_version? You can see samples of the
> kernel_version here http://klive.cpushare.com/2.6.15/ . That's the
> string that is being searched against both PREEMPT and SMP.

Try something like this where attname is the column name and tablename is,
well, the tablename:

db=> select most_common_vals from pg_stats where tablename = 'region' and attname = 'province';
most_common_vals
------------------
{ON,NB,QC,BC}

Note that there's a second column most_common_freqs and to do this would
really require doing a weighted average based on the frequencies.

--
greg