On 12 November 2014 07:54, David Rowley <dgrowle...@gmail.com> wrote: > On Tue, Nov 11, 2014 at 9:29 PM, Simon Riggs <si...@2ndquadrant.com> wrote: >> >> >> This plan type is widely used in reporting queries, so will hit the >> mainline of BI applications and many Mat View creations. >> This will allow SELECT count(*) FROM foo to go faster also. >> > > We'd also need to add some infrastructure to merge aggregate states together > for this to work properly. This means that could also work for avg() and > stddev etc. For max() and min() the merge functions would likely just be the > same as the transition functions.
Do you mean something like a "subtotal" or "intermediate combination" functon? I guess we'd need the same thing to make intermediate aggregates work during a sort? -- Simon Riggs http://www.2ndQuadrant.com/ PostgreSQL Development, 24x7 Support, Training & Services -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
