> Well, you're joining the entire two tables, so yes, the seq scan might
> be faster.
My mistake. When composing the email to state the problem, I accidentally
gave a wrong versionof the join query.
Here is the corrected version, which still has the sequential scan...
explain select notificationID from NOTIFICATION n, ITEM i where n.itemID
= i.itemID andi.projectID = 12;
QUERY PLAN
--------------------------------------------------------------------------------------------------
Hash Join (cost=2237.54..15382.32 rows=271 width=44)
Hash Cond: ("outer".itemid = "inner".itemid)
-> Seq Scan on notification n (cost=0.00..12023.71 rows=223671 width=48)
-> Hash (cost=2235.31..2235.31 rows=895 width=4)
-> Index Scan using item_ix_item_4_idx on item i
(cost=0.00..2235.31 rows=895width=4)
Index Cond: (projectid = 12)
---------------------------(end of broadcast)---------------------------
TIP 7: don't forget to increase your free space map settings
