On 4:12 pm 07/23/08 "Francisco Reyes" <lists@stringsutils.com> wrote:
> Also, that plan is only 3 seconds.
Minor update.
A co-worker is using another DB.. and re-running my query after he did his
work.. now the query using the index scans takes 2 minutes instead of 3
seconds. 3 seconds was likely data cached.
To re-list the times..
Sequential scan 12 minutes
Bitmap scans 30 minutes
index scan with not bitmap 2 minutes
It is worth pointing out that the bitmap test was run AFTER the sequential
scan test.. right after it.. so it should have benefited from OS caching.
The join_ids table fits completely in memory.
select pg_size_pretty(pg_total_relation_size('join_ids'));
pg_size_pretty
----------------
291 MB
(1 row)
par4mo=# select pg_size_pretty(pg_relation_size('join_ids'));
pg_size_pretty
----------------
94 MB
(1 row)