-Original Message-
From: Matthew Wakeling [mailto:matt...@flymine.org]
On Thu, 14 May 2009, Ow Mun Heng wrote:
>> Shouldn't BITMAP indexes come into play?
>>
>> Does having one index w/ 3 parameters being better than 3 index w/ 3
>> different parameters be better for BITMAP index seeks?
On Thu, 14 May 2009, Ow Mun Heng wrote:
Shouldn't BITMAP indexes come into play?
Does having one index w/ 3 parameters being better than 3 index w/ 3
different parameters be better for BITMAP index seeks?
I'll let someone correct me if I'm wrong, but using a single index that
exactly covers y
-Original Message-
From: pgsql-performance-ow...@postgresql.org [mailto:pgsql-performance- A
much
>> better index to answer your query is (city_id, house_id, floor_id) -
>> then it can just look up straight away. Instead of the index returning
>> 20 rows to check, it will return ju
Matthew Wakeling wrote:
Thomas, the order of columns in the index matters. The index is
basically a tree structure, which resolves the left-most column before
resolving the column to the right of it. So to answer your query, it
will resolve the city_id, then it will have to scan almost all of t
On Tue, 12 May 2009, Greg Smith wrote:
You should test what happens if you reduce the index to just being
(city_id,street_id).
I think you're missing the point a little here. The point is that Thomas
is creating an index on (city_id, street_id, house_id, floor_id) and
running a query on (city
First off, is there a way to pre-filter some of this data, by a view,
temporary table, partitioned indexes or something.
Secondly, one of the problems seems to be the size of the data and its
index, how can I calulate how much space a particular part of the index
needs in memory? maybe I co
On Tue, 12 May 2009, Thomas Finneid wrote:
on a database with 260 GB of data and an index size of 109GB on separate raid
disks. there are
85 city_ids, 2000
street_ids per city,
20 house_ids per street per city
5 floor_ids per house_ per street per city
You shou
Hi
have the following table (theoretical)
table apartment_location (
city_idint,
street_id int,
house_id int,
floor_id int,
owner string
...
)
index .. ( city_id, street_id, house_id, floor_id ) tablespc indexspace;
on a database w
