This is a little strange - my response to this post apparently got lost in the net?? I haven't received it back through the list nor it's visible in the archieve. Yet, my exim logfile contains entry indicating 'delivery complited'??? But to the point. All the EXPLAIN ANALISE I did on posggres v8.1.4 - plain *.deb binary install from debian network repository. So if version v8.1 was expected to behave any differently, it doesn't. But may be the reduction improvement are in some pre-8.2 versions? -R On Mon, 2006-08-28 at 10:46 -0400, Tom Lane wrote: > Alban Hertroys <alban@xxxxxxxxxxxxxxxxx> writes: > > There's practically no difference between SELECT 1 FROM ... and SELECT * > > FROM ...; the only added costs (AFAIK) are for actually fetching the > > column values and such. Pretty cheap operations. > > You're both glossing over exactly the wrong thing, particularly seeing > that Rafal appears to be using 8.0 or older which hasn't got 8.1's > significant reductions in targetlist evaluation costs. > > regards, tom lane > > ---------------------------(end of broadcast)--------------------------- > TIP 3: Have you checked our extensive FAQ? > > http://www.postgresql.org/docs/faq -- -R
