This must be really simple, but I just can't get it :-(
I have a table (a) with a single column (x):
Table "a"
Attribute | Type | Modifier
-----------+----------+----------
x | smallint |
Index: a_idx
Index "a_idx"
Attribute | Type
-----------+----------
x | smallint
btree
The table has 10000000 rows....
Now, how come, when I do:
explain select * from a where x=3;
it says:
Seq Scan on bset (cost=100000000.00..100175934.05 rows=303 width=2)
Why is it not using a_idx???
I even tried set enable_seqscan to off - makes no difference :-(
Any idea what is going on?
Thanks a lot!
Dima