i have wondered myself. i wouldn't do it through pgAdmin (not sure what the best test it, but i thought psql from the same machine might be better--see below). anyway, the funny thing is that if you concatenate them the time drops: ~% time psql -dXXX -hYYY -UZZZ -c"select consumer_id from consumer" -o /dev/null psql -dXXX -hYYY -UZZZ -c"select consumer_id from consumer" -o 0.09s user 0.01s system 29% cpu 0.341 total ~% time psql -dXXX -hstgdb0 -p5432 -Umnp -c"select consumer_id,consumer_id,consumer_id,consumer_id,consumer_id,consumer_id, consumer_id,consumer_id from consumer" -o /dev/null psql -dXXX -hYYY -UZZZ -o /dev/null 0.76s user 0.06s system 45% cpu 1.796 total ~% time psql -dXXX -hYYY -UZZZ -c"select consumer_id||consumer_id||consumer_id||consumer_id||consumer_id||consume r_id||consumer_id||consumer_id from consumer" -o /dev/null psql -dXXX -hYYY -UZZZ -o /dev/null 0.18s user 0.04s system 20% cpu 1.061 total > -----Original Message----- > From: pgsql-performance-owner@xxxxxxxxxxxxxx > [mailto:pgsql-performance-owner@xxxxxxxxxxxxxx] On Behalf Of Tom Darci > Sent: Wednesday, October 25, 2006 10:21 AM > To: pgsql-performance@xxxxxxxxxxxxxx > Subject: [PERFORM] query slows down drastically with > increased number of fields > > Hello All- > > We have a question about numbers of fields in the select > clause of a query and how that affects query speed. > The following query simply selects the primary key field > from a table with 100,000 records: > > ------------------------------------------------------------ > select p.opid > FROM > ott_op p > > ------------------------------------------------------------ > > It runs in about half a second (running in PgAdmin... the > query run time, not the data retrieval time) > > When we change it by adding fields to the select list, it > slows down drastically. This version takes about 3 seconds: > > ------------------------------------------------------------ > select p.opid, p.opid, p.opid, p.opid, p.opid, p.opid, > p.opid, p.opid, p.opid, p.opid, p.opid > FROM > ott_op p > > ------------------------------------------------------------ > > The more fields we add, the slower it gets. > > My guess is that we are missing a configuration setting... > any ideas? > Any help much appreciated. > > Thanks, > -Tom >
