Hi, Joe, Joe Lester wrote: > Aggregate (cost=22695.28..22695.28 rows=1 width=0) (actual > time=2205.688..2205.724 rows=1 loops=1) > -> Seq Scan on purchase_order_items (cost=0.00..21978.08 rows=286882 > width=0) (actual time=0.535..2184.405 rows=7458 loops=1) > Filter: (expected_quantity > 0) The query planner estimates that your filter will hit 286882 rows, while in reality it hits only 7458 rows. That's why the query planer chooses a sequential scan. It seems that the statistics for the column expected_quantity are off. My suggestions: - make shure that the statistics are current by analyzing the table appropriately (e. G. by using the autovacuum daemon from contrib). - increase the statistics target for this column. - if you run this query very often, an conditional index might make sense: CREATE INDEX purchase_order_having_quantity_idx ON purchase_order_items (expected_quantity) WHERE expected_quantity > 0; HTH, Markus -- Markus Schaber | Logical Tracking&Tracing International AG Dipl. Inf. | Software Development GIS Fight against software patents in EU! www.ffii.org www.nosoftwarepatents.org
