[Tobias Brox - Tue at 11:02:07AM +0800] > test=# explain select * from mock where b is NULL; > QUERY PLAN > -------------------------------------------------------------------- > Seq Scan on mock (cost=100000000.00..100000020.00 rows=6 width=8) > Filter: (b IS NULL) > (2 rows)
(...) > ---------------------------(end of broadcast)--------------------------- > TIP 9: the planner will ignore your desire to choose an index scan if your > joining column's datatypes do not match That tip helped me :-) test=# explain select * from mock where (b IS NULL)=true; QUERY PLAN ---------------------------------------------------------------------- Index Scan using b_is_null on mock (cost=0.00..4.68 rows=1 width=8) Index Cond: ((b IS NULL) = true) (2 rows) -- Tobias Brox, Beijing ---------------------------(end of broadcast)--------------------------- TIP 3: if posting/reading through Usenet, please send an appropriate subscribe-nomail command to [EMAIL PROTECTED] so that your message can get through to the mailing list cleanly