> and here's my query
>
> select * from ticket
> where created between '2012-12-19 00:00:00' and '2012-12-20 00:00:00'
>
> This was working fine until the number of records started to grow (about 5 million) and now it's taking forever to
return.
>
> Explain analyze reveals this:
>
> "Index Scan using ticket_1_idx on ticket (cost=0.00..10202.64 rows=52543 width=1297) (actual time=0.109..125.704
rows=53340loops=1)"
> " Index Cond: ((created >= '2012-12-19 00:00:00+00'::timestamp with time zone) AND (created <= '2012-12-20
00:00:00+00'::timestampwith time zone))"
> "Total runtime: 175.853 ms"
> Nothing works. What am I doing wrong? why is it selecting sequential scan? the indexes are supposed to make the query
fast.Anything that can be done to optimize it?
It is not selecting sequential scan, you're looking at an index scan. That should be pretty fast, and it isn't that
slow- that's still sub-second performance (0.176s).
Is that explain from the correct table? According to the results there are but 53 thousand rows in it, not anywhere
near5 million.
Perhaps your index got bloated? Do you have any long-running transactions still active that prevent cleaning up
deprecatedindex entries? If that's the case, close the application that keeps that connection open and run a vacuum.
Are you vacuuming that table often enough?
If none of that helps, perhaps a REINDEX does.
Is that a dedicated database machine or is it also doing other stuff that's eating up resources?
You didn't mention what version of Postgres you're on or what OS you're using.
Alban Hertroys
--
Screwing up is an excellent way to attach something to the ceiling.