On Thu, Mar 10, 2011 at 7:32 PM, Bruce Momjian <br...@momjian.us> wrote: > Robert Haas wrote: >> 2010/11/25 pasman pasma?ski <pasma...@gmail.com>: >> >>I've seen this as well be a performance issue, in particular with >> >>partitioned tables. >> >>Out of habit I now write functions that always cache the value of the >> >>function in >> >>a variable and use the variable in the actual query to avoid this >> >>particular "gotcha". >> > >> > subquery may be used to cache constants: >> > >> > SELECT a_date >> > ?FROM test >> > ?WHERE a_date=(SELECT current_date); >> > >> > >> > "Seq Scan on test1 ?(cost=0.01..10.76 rows=5 width=4)" >> > " ?Filter: (a_date = $0)" >> > " ?InitPlan 1 (returns $0)" >> > " ? ?-> ?Result ?(cost=0.00..0.01 rows=1 width=0)" >> >> Interesting. So we pull a subquery out and treat it as an initplan, >> but not a stable function? Hmm... > > I assume this is _not_ a TODO.
Dunno, not sure. -- Robert Haas EnterpriseDB: http://www.enterprisedb.com The Enterprise PostgreSQL Company -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
