Re: SQL timestamp to date cast

From: Michael Fuhr <mike(at)fuhr(dot)org>
To: Andrei Bintintan <klodoma(at)ar-sd(dot)net>
Cc: pgsql-sql(at)postgresql(dot)org
Subject: Re: SQL timestamp to date cast
Date: 2005-01-20 09:33:31
Message-ID: 20050120093331.GA37672@winnie.fuhr.org
Views: Raw Message | Whole Thread | Download mbox | Resend email
Thread:
Lists: pgsql-sql

On Thu, Jan 20, 2005 at 10:52:50AM +0200, Andrei Bintintan wrote:

> SELECT DISTINCT(nummer)
> FROM user_action
> WHERE datetime::date='11/11/2004' AND id_action IN (5,6,9)
>
> Now, datetime has the type timestamp. How can I make an index or write
> different this query so that it runs faster?

You could create an index on datetime and rewrite your queries:

CREATE INDEX user_action_datetime_idx ON user_action (datetime);

SELECT DISTINCT(nummer)
FROM user_action
WHERE datetime >= '11/11/2004' AND datetime < '11/12/2004'
AND id_action IN (5,6,9);

Another possibility would be to create a functional index on datetime:

CREATE INDEX user_action_date_idx ON user_action (date(datetime));

SELECT DISTINCT(nummer)
FROM user_action
WHERE date(datetime) = '11/11/2004' AND id_action IN (5,6,9);

--
Michael Fuhr
http://www.fuhr.org/~mfuhr/

In response to

Responses

Browse pgsql-sql by date

  From Date Subject
Next Message Silke Trissl 2005-01-20 09:39:47 Problem on Geometric functions
Previous Message Andrei Bintintan 2005-01-20 08:52:50 SQL timestamp to date cast