On 5 April 2014 04:18, Tom Lane <t...@sss.pgh.pa.us> wrote: > Greg Stark <st...@mit.edu> writes: >> Well in many cases stype will just be internal for many of them. That >> doesn't mean they're the same. > >> Hm, I suppose it might if they have the same sfunc. > >> This is actually where I started but we concluded that we needed some >> declaration that the aggregates were actually related and would interpret >> the state the same way and not just that it happened to use the same >> storage format. > > Well, in practice you'd need to also compare the input datatype (consider > polymorphic aggregates) and initcond. But the sfunc isn't told which > finalfunc will be applied, so any aggregates that share the same sfunc and > have the other conditions the same *must* have the identical transition > data behavior. I don't see any reason to invent new syntax, and there > are good reasons not to if we don't have to.
Definitely happy not to have additional syntax. So we can just dynamically group the aggregates together. -- 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
