On Wed, Mar 27, 2019 at 08:15:35PM -0700, Andres Freund wrote:
Hi,
On 2019-03-27 21:13:46 +0100, Tomas Vondra wrote:
On Wed, Mar 27, 2019 at 12:32:34PM -0700, Peter Geoghegan wrote:
> On Wed, Mar 27, 2019 at 12:04 PM Andres Freund <and...@anarazel.de> wrote:
> > Congrats, this was long in the making!
>
> +1
>
Thanks! I guess it's a Gordie Howe of our patches.
Btw, do you have plans to work on using more of this information during
join planning? Or at least an estimate of how much work that'd be?
Yes, I'd like to use more of this info in join estimation. I don't have
an exact plan how to do that - so if anyone has ideas regarding this,
I'd love to hear them.
An obvious option is to add statistics covering multiple tables (the
syntax is already designed with that in mind). But I have a feeling there
are things we can do without that, e.g. using multivariate MCV lists in
eqjoinsel roughly the same way we use per-column MCV lists, etc.
regards
--
Tomas Vondra http://www.2ndQuadrant.com
PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services
