Arshavir Grigorian <ag@xxxxxxxxx> writes: > I have a query that when run on similar tables in 2 different databases > either uses the index on the column (primary key) in the where clause or > does a full table scan. The structure of the tables is the same, except > that the table where the index does not get used has an extra million > rows (22mil vs 23mil). I'd say you initialized the second database in a non-C locale. The planner is clearly well aware that the seqscan is going to be expensive, so the explanation has to be that it does not have a usable index available. regards, tom lane
