Edoardo Ceccarelli <[EMAIL PROTECTED]> writes: > This is the query: > select max(KA) from annuncio > > field KA is indexed and is int4, > > explaining gives: > explain select max(KA) from annuncio; > QUERY PLAN > ----------------------------------------------------------------------- > Aggregate (cost=21173.70..21173.70 rows=1 width=4) > -> Seq Scan on annuncio (cost=0.00..20326.76 rows=338776 width=4) > (2 rows) > > > wasn't supposed to do an index scan? it takes about 1sec to get the result.
This is a known misfeature of max() in postgresql, see... http://archives.postgresql.org/pgsql-performance/2003-12/msg00283.php -- # James Antill -- [EMAIL PROTECTED] :0: * ^From: [EMAIL PROTECTED] /dev/null ---------------------------(end of broadcast)--------------------------- TIP 9: the planner will ignore your desire to choose an index scan if your joining column's datatypes do not match
