On 06/06/2018 04:01 PM, Andres Freund wrote:
Hi,
On 2018-06-06 15:58:16 +0200, Tomas Vondra wrote:
The other issue is that serialize/deserialize is only a part of a problem -
you also need to know how to do "combine", and not all aggregates can do
that ... (certainly not in universal way).
There are several schemes where only serialize/deserialize are needed,
no? There are a number of fairly sensible schemes where there won't be
multiple transition values for the same group, no?
Possibly, not sure what schemes you have in mind exactly ...
But if you know there's only a single transition value, why would you
need serialize/deserialize at all. Why couldn't you just finalize the
value and serialize that?
regards
--
Tomas Vondra http://www.2ndQuadrant.com
PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services
