Marinos Yannikos <mjy@xxxxxxxxxxx> writes: > Marinos Yannikos wrote: >> (what exactly does ANALYZE look at for text columns? in our case, about >> 7% of the rows match the index condition, so it seems that left-anchored >> regexp/like matches are not evaluated using the gathered >> most-common-value list at all) > oops, I think I gave myself the answer there. Of course the > most-common-value list will not help if all the values that match the > "bad" index condition exist only once, but have a common prefix... The costing is really done off the range condition ((e >= 'ean'::text) AND (e < 'eao'::text) in your example). I wouldn't think it would have such a hard time getting a good rowcount estimate for that. Maybe you need to bump up the statistics target for that column? regards, tom lane -- Sent via pgsql-performance mailing list (pgsql-performance@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-performance
