2010/9/1 Tom Lane <t...@sss.pgh.pa.us>: > Pavel Stehule <pavel.steh...@gmail.com> writes: >> 2010/9/1 Tom Lane <t...@sss.pgh.pa.us>: >>> Well, you can build your own version of array_agg with the same >>> implementation, except you mark the transition function as strict ... > >> I am checking this now, and it is not possible - it needs a some >> initial value and there isn't possible to set a "internal" value. > > Well, you can cheat a bit ... > > regression=# create or replace function array_agg_transfn_strict(internal, > anyelement) returns internal as 'array_agg_transfn' language internal > immutable; > CREATE FUNCTION > regression=# create aggregate array_agg_strict(anyelement) (stype = internal, > sfunc = array_agg_transfn_strict, finalfunc = array_agg_finalfn); > CREATE AGGREGATE > regression=# create or replace function array_agg_transfn_strict(internal, > anyelement) returns internal as 'array_agg_transfn' language internal strict > immutable; > CREATE FUNCTION >
nice dark trick :) - but it doesn't work ERROR: aggregate 16395 needs to have compatible input type and transition type postgres=# Pavel > regards, tom lane > -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
