On Wed, 31 Mar 2010, Faheem Mitha wrote:
On Tue, 30 Mar 2010, Robert Haas wrote:
On Tue, Mar 30, 2010 at 12:30 PM, Faheem Mitha <faheem@xxxxxxxxxxxxx>
You might need to create some indices, too.
Ok. To what purpose? This query picks up everything from the
tables and the planner does table scans, so conventional wisdom
and indeed my experience, says that indexes are not going to be so
useful.
There are situations where scanning the entire table to build up a
hash table is more expensive than using an index. Why not test it?
Certainly, but I don't know what you and Robert have in mind, and I'm not
experienced enough to make an educated guess. I'm open to specific
suggestions.
Try creating an index on geno on the columns that are being used for the
join.
Ok, I'll try that. I guess the cols in question on geno are idlink_id and
anno_id. I thought that I already had indexes on them, but no. Maybe I had
indexes, but removed them.
Looking at this more closely, idlink_id and anno_id are primary keys, so
already have indexes on them, so my understanding (from the docs) is there
is no purpose in creating them. That's why I removed the indexes that were
there (back last August, actually, according to my logs). Anyway, doesn't
look there is anything I can do here. Does anyone have additions or
corrections to this?
Regards, Faheem.
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