That's not what I wrote. My point was that we *should* store the digests themselves, otherwise we just introduce additional errors into the estimates, because it discards the weights/frequencies.
Sorry. I meant to write "no reason to not store the digests"
On Fri, Nov 01, 2019 at 11:11:13AM -0300, Igor Calabria wrote: >Yeah, I agree that there's no reason to store the digests themselves and I >really liked the idea of it being optional.
That's not what I wrote. My point was that we *should* store the digests themselves, otherwise we just introduce additional errors into the estimates, because it discards the weights/frequencies.
>If it turns out that memory consumption on real workloads is small enough, >it could eventually be turned on by default. >
Maybe, but it's not just about memory consumption. CPU matters too.
regards
-- Tomas Vondra http://www.2ndQuadrant.com PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services
