Steve wrote:
-------- Original-Nachricht --------
Datum: Sat, 11 Sep 2010 11:08:00 -0400
Von: Lew <no...@lewscanon.com>
An: pgsql-sql@postgresql.org
Betreff: Re: [SQL] Question regarding indices
On 09/11/2010 08:29 AM, Steve wrote:
I have a small question about the order of values in a query.
Assume I have a table with the following fields:
uid INT,
data BIGINT,
hits INT
And an unique index on (uid, data). I use libpq C API to query
data from the table. The query is something like this:
SELECT uid,data,hits FROM mytable WHERE uid=2
AND data IN (2033,2499,590,19,201,659)
Would the speed of the query be influenced if I would sort the data?
What do you mean by "sort the data"? Which data?
I mean sorting the values in the brackets. Instead of:
SELECT uid,data,hits FROM mytable WHERE uid=2 AND data IN
(2033,2499,590,19,201,659)
I would then send this here:
SELECT uid,data,hits FROM mytable WHERE uid=2 AND data IN
(19,201,590,659,2033,2499)
Off course this is a small dataset but the query usually has thousands of
elements and not only the above 6 elements.
If there will be thousands; why not create a temp table containing these
values then join to table - might that be faster?
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