On Wed, Nov 25, 2009 at 4:13 PM, Luca Tettamanti <kronos.it@gmail.com> wrote:
DELETE FROM t1 WHERE EXISTS (SELECT 1 FROM t2 WHERE t1.annotation_id = t2.annotation_id)
performs event better:
Seq Scan on t1 (cost=0.00..170388415.89 rows=22937406 width=6) (actual time=272.625..561241.294 rows=26185953 loops=1)
Filter: (subplan)
SubPlan
-> Index Scan using t2_idx on t2 (cost=0.00..1113.63 rows=301 width=0) (actual time=0.008..0.008 rows=1 loops=45874812)
Index Cond: ($0 = annotation_id)
Total runtime: 629426.014 ms
(6 rows)
Have you tried:
DELETE FROM t1 USING t2 WHERE t1.annotation_id = t2.annotation_id;
?
DELETE FROM t1 USING t2 WHERE t1.annotation_id = t2.annotation_id;
?
--
GJ
