On Thu, 7 Jan 2010, Jesper Krogh wrote:
If disk seeks are killing you a kinda crazy idea would be to
duplicate the table - clustering one by (id1) and
the other one by an index on (id2) and unioning the
results of each.
That's doubling the disk space needs for the table. Is there any odds
that
Jesper,
the whole idea of bitmap index scan is to optimize heap access, so it ruins
any ordering, returned by index. That's why our new KNNGist, which returned
ordered index tuples doesn't supports bitmap index scan (note, this is only
for knn search).
Oleg
On Wed, 6 Jan 2010, Robert Haas wrote
Jesper Krogh wrote:
Is it possible to get PG to tell me, how many rows that fits in a
disk-page. All columns are sitting in "plain" storage according to \d+
on the table.
select relname,round(reltuples / relpages) as "avg_rows_per_page" from
pg_class where relpages > 0;
--
Greg Smith2nd
Ron Mayer wrote:
>> ...The inner sets are on average 3.000 for
>> both id1 and id2 and a typical limit would be 100, so if I could convince
>> postgresql to not fetch all of them then I would reduce the set retrieved
>> by around 60. The dataset is quite large so the random query is not very
>> lik
On Wed, Jan 6, 2010 at 2:10 PM, Jesper Krogh wrote:
> Hi.
>
> I have a table that consists of somewhere in the magnitude of 100.000.000
> rows and all rows are of this tuples
>
> (id1,id2,evalue);
>
> Then I'd like to speed up a query like this:
>
> explain analyze select id from table where id1 =
Jesper Krogh wrote:
> I have a table that consists of somewhere in the magnitude of 100.000.000
> rows and all rows are of this tuples
>
> (id1,id2,evalue);
>
> Then I'd like to speed up a query like this:
>
> explain analyze select id from table where id1 = 2067 or id2 = 2067 order
> by evalue
Hi.
I have a table that consists of somewhere in the magnitude of 100.000.000
rows and all rows are of this tuples
(id1,id2,evalue);
Then I'd like to speed up a query like this:
explain analyze select id from table where id1 = 2067 or id2 = 2067 order
by evalue asc limit 100;
