What am I missing that causes this to resort to sorting on disk? obc=# select version(); version ---------------------------------------------------------------------------------------------------------- PostgreSQL 8.3.7 on x86_64-redhat-linux-gnu, compiled by GCC gcc (GCC) 4.1.2 20071124 (Red Hat 4.1.2-42) (1 row) Time: 43.920 ms > ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- > Limit (cost=1063641.92..1063643.47 rows=20 width=13) (actual time=422710.147..422711.328 rows=20 loops=1) > -> Unique (cost=1063641.92..1064133.33 rows=6320 width=13) (actual time=422710.022..422711.127 rows=20 loops=1) > -> Sort (cost=1063641.92..1063887.62 rows=98282 width=13) (actual time=422710.014..422710.696 rows=172 loops=1) > Sort Key: cpn.value > Sort Method: external merge Disk: 304008kB > -> Nested Loop (cost=647.20..1061026.67 rows=98282 width=13) (actual time=61.029..71867.921 rows=9627373 loops=1) > -> HashAggregate (cost=647.20..648.15 rows=95 width=4) (actual time=60.950..64.350 rows=596 loops=1) > -> Hash Join (cost=4.59..646.96 rows=95 width=4) (actual time=0.352..57.210 rows=596 loops=1) > Hash Cond: (cb.client_id = c.id) > -> Seq Scan on contact_block cb (cost=0.00..596.31 rows=12031 width=8) (actual time=0.015..26.757 rows=10323 loops=1) > -> Hash (cost=4.58..4.58 rows=1 width=4) (actual time=0.064..0.064 rows=1 loops=1) > -> Seq Scan on clients c (cost=0.00..4.58 rows=1 width=4) (actual time=0.021..0.055 rows=1 loops=1) > Filter: ((name)::text = 'Kmart Pharmacies, Inc.'::text) > -> Index Scan using extra_import_param_blk_item_tag on extra_import_param cpn (cost=0.00..11039.67 rows=9777 width=17) (actual time=0.057..61.769 rows=16153 loops=596) > Index Cond: ((cpn.block_id = cb.id) AND ((cpn.tag)::text = 'PATNAME'::text)) > Total runtime: 422920.026 ms > (16 rows) > > Time: 422924.289 ms > obc=# show sort_mem; > work_mem > ---------- > 900MB > (1 row) -- Sent via pgsql-general mailing list (pgsql-general@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general