Erik Norvelle <signups@xxxxxxxxxxxx> writes: >>> it=> explain select codelemm, sectref, count(codelemm) from indethom > group by codelemm, sectref; >>> QUERY PLAN >>> ----------------------------------------------------------------------- > --------- >>> GroupAggregate (cost=2339900.60..2444149.44 rows=1790528 width=13) >>> -> Sort (cost=2339900.60..2364843.73 rows=9977252 width=13) >>> Sort Key: codelemm, sectref >>> -> Seq Scan on indethom (cost=0.00..455264.52 rows=9977252 > width=13) Actually the painful part of that is the sort. If you bump up sort_mem enough it will eventually switch over to a HashAggregate with no sort, which may be a better plan if there's not too many groups (is the estimate of 1.79 million on the mark at all??) regards, tom lane
