Re: GiST index performance

dforum  writes:
> If you analyse query plan, you see that most of the time are lost during 
> sequencial scan, and you have 2 seq scan.

I think you missed the loops count.

>>          ->  Index Scan using location_object_start_gist on location l1
>>                (cost=0.00..4.16 rows=150 width=65)
>>                (actual time=3.354..10.757 rows=3 loops=211880)
>>                Index Cond: ((l1.objectid = l2.objectid) AND 
>> (l2.intermine_start <= l1.intermine_start) AND (l2.intermine_end >= 
>> l1.intermine_start))

This indexscan is accounting for 10.757 * 211880 msec, which is 99%
of the runtime.

			regards, tom lane