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From:سيد هادی راستگوی حقی Date:February 3 2006 6:57pm
Subject:Re: Query Speed
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Dear all,
Thanks for your replies.

The main table for me is traffic_log. I use combination of recipient_id and
mobile_retry fields to uniquely identify each row in the traffic_log and use
the same combination on status_log as my foreign key to traffic_log.
Each message is saved as a row in traffic_log and its statuses are stored in
status_log.
The make me join these tow tables on both fields to find each message's
statuses.

For performing fast query, I always first select messages from traffic_log
becuase of it's indices and then select last status for each message.
I mean that i perform 2 separate queries.

But the problem arises when i want to search on statuses, so i have to join
these large tables and then select base on my status constraint and then
sort them base on their times. these parts are time consuming and i want to
make them fast.

As i said before, you may suggest me to restructure my tables.
I will appreciate your suggestions.

Thanks for your interest to solving my problem.

On 2/2/06, SGreen@unimin.com <SGreen@stripped> wrote:
>
>
> Sorry, but you gave us a "best guess" situation. Your tables do not have
> any PRIMARY KEYs defined on them so I had to guess at what made each row in
> each table unique from all other rows in that table based only on your
> sample query.
>
> What value or combination of values will allow me to uniquely identify a
> single record from each table?  Armed with that information I can rework my
> solution to accurately identify what you want to know. My suggestion is that
> you add two integer-based auto_increment columns, one to each table, and
> make them the PRIMARY KEYs and foreign keys as appropriate.
>
> For example: What makes a single row of traffic_log different from each of
> the others? Is it the `recipient_id` column or a combination of values? Same
> for the `status_log` table. What makes each row different from all others?
> How do I uniquely identify a single row in `traffic_log` that corresponds to
> any random row from `status_log`?
>
> Yours,
>
> Shawn Green
> Database Administrator
> Unimin Corporation - Spruce Pine
>
>
>
> سيد هادی راستگوی حقی <hadi.rastgou@stripped> wrote on 02/02/2006 01:14:35
> AM:
>
> > Thanks for your suggestion,
> > I forget to tell that each message in traffic_log may has at least 2
> status
> > in status_log and I use to columns "recipients_id" and "mobile_retry"
> > to uniquely find each message's statuses.
> > May be I have to change my tables structure. I don't know.
> >
> > It's really important for me to show each message with it's last status.
> So
> > I have to use group by because in other way such as
> >
> > SELECT * FROM status_log
> > ORDER BY time;
> >
> > returns all statuses in order of time regards to multiple statuses for
> any
> > message. so I think that the query may be like this
> >
> > (SELECT status, recipient_id, time, mobile_retry FROM status_log GROUP
> BY
> > recipient_id HAVING time=MAX(time)) AS sts*
> > JOIN traffic_log ON traffic_log.recipient_id=sts.recipient_id AND
> > traffic_log.mobile_retry=sts.mobile_retry
> >
> > *sts --> to find last status of each message
> >
> >
> > On 2/1/06, SGreen@unimin.com <SGreen@stripped> wrote:
> > >
> > >
> > >
> > > سيد هادی راستگوی حقی <hadi.rastgou@gmail.com> wrote on 02/01/2006
> 11:07:49
> > > AM:
> > >
> > > > Dear All,
> > > > I need your suggestions please.
> > > >
> > > > have to large tables with these schemas:
> > > >
> > > >  Table: traffic_log
> > > > Create Table: CREATE TABLE `traffic_log` (
> > > >   `recipient_id` int(11) NOT NULL default '0',
> > > >   `retry` smallint(4) NOT NULL default '0',
> > > >   `mobile_retry` tinyint(1) NOT NULL default '0',
> > > >   `orig` varchar(13) default NULL,
> > > >   `dest` varchar(13) default NULL,
> > > >   `message` text,
> > > >   `account_id` int(11) NOT NULL default '0',
> > > >   `service_id` int(11) NOT NULL default '0',
> > > >   `dir` enum('IN','OUT') NOT NULL default 'IN',
> > > >   `plugin` varchar(30) NOT NULL default 'UNKNOWN',
> > > >   `date_entered` datetime NOT NULL default '0000-00-00 00:00:00',
> > > >   `replied` tinyint(4) default '0',
> > > >   KEY `account_id` (`account_id`,`recipient_id`,`mobile_retry`),
> > > >   KEY `account_id_2` (`account_id`,`date_entered`)
> > > > ) ENGINE=MyISAM DEFAULT CHARSET=utf8
> > > >
> > > > Table: status_log
> > > > Create Table: CREATE TABLE `status_log` (
> > > >   `recipient_id` int(11) NOT NULL default '0',
> > > >   `retry` smallint(4) NOT NULL default '0',
> > > >   `mobile_retry` tinyint(1) NOT NULL default '0',
> > > >   `status` smallint(5) NOT NULL default '0',
> > > >   `time` datetime NOT NULL default '0000-00-00 00:00:00',
> > > >   `smsc` varchar(20) NOT NULL default '',
> > > >   `priority` tinyint(2) unsigned NOT NULL default '0',
> > > >   `ack` varchar(30) NOT NULL default '',
> > > >   KEY `recipient_id_2`
> (`recipient_id`,`mobile_retry`,`time`,`status`),
> > > >   KEY `time` (`time`,`recipient_id`,`mobile_retry`,`status`)
> > > > ) ENGINE=MyISAM DEFAULT CHARSET=utf8
> > > >
> > > > I want to execute a query to find out each last message's status. So
> my
> > > > query is :
> > > >
> > > > select * from traffic_log LEFT JOIN status_log ON
> > > > traffic_log.recipient_id=status_log.recipient_id and
> > > > traffic_log.mobile_retry=status_log.mobile_retry WHERE  account_id =
> 32
> > > > group by status_log.recipient_id HAVING time=max(time) order by
> time;
> > > >
> > > > And MySQL explanation about this query is:
> > > > *************************** 1. row ***************************
> > > >            id: 1
> > > >   select_type: SIMPLE
> > > >         table: traffic_log
> > > >          type: ref
> > > > possible_keys: account_id,account_id_2
> > > >           key: account_id
> > > >       key_len: 4
> > > >           ref: const
> > > >          rows: 1049598
> > > >         Extra: Using temporary; Using filesort
> > > > *************************** 2. row ***************************
> > > >            id: 1
> > > >   select_type: SIMPLE
> > > >         table: status_log
> > > >          type: ref
> > > > possible_keys: recipient_id_2
> > > >           key: recipient_id_2
> > > >       key_len: 5
> > > >           ref: smse.traffic_log.recipient_id,
> > > smse.traffic_log.mobile_retry
> > > >          rows: 2
> > > >         Extra:
> > > >
> > > > as you see return records are 1049598.
> > > >
> > > > But it's very slow.
> > > >
> > > > Do you have any suggestions to fast it?
> > > >
> > > > --
> > > > Sincerely,
> > > > Hadi Rastgou
> > > > <a href="http://www.spreadfirefox.com/?q=affiliates&amp;
> > id=0&amp;t=1<http://www.spreadfirefox.com/?q=affiliates&id=0&t=1>
> > > ">Get
> > > > Firefox!</a>
> > >
> > > This is another variant of the groupwise maximum pattern of query:
> > >
> > > http://dev.mysql
> > > .com/doc/refman/4.1/en/example-maximum-column-group-row.html
> > >
> > > My favorite way to write these kinds of queries is to make a temporary
> > > table (or more if needed) identifying the group and max-per-group then
> using
> > > that temp table to create the final query. In your case, the group is
> the
> > > recipient_id and the max-per-group will be MAX(`time`);
> > >
> > > CREATE TEMPORARY TABLE tmpLastStatusTimes SELECT
> > >     `recipient_id`
> > >    ,MAX(`time`) as lastmsg
> > > FROM status_log;
> > >
> > > CREATE TEMPORARY TABLE tmpLastStatuses SELECT
> > >         sl.*
> > > FROM status_log sl
> > > INNER JOIN tmpLastStatusTimes lst
> > >         ON lst.`recipient_id` = sl.`recipient_id`
> > >         AND lst.lastmsg = sl.`time`;
> > >
> > > SELECT * from traffic_log
> > > LEFT JOIN tmpLastStatuses
> > >         ON traffic_log.recipient_id=tmpLastStatuses.recipient_id
> > >         AND traffic_log.mobile_retry=tmpLastStatuses.mobile_retry
> > > WHERE  account_id = 32
> > > order by time;
> > >
> > > DROP TEMPORARY TABLE tmpLastStatuses, tmpLastStatusTimes;
> > >
> > > In your specific sample, you were only looking for messages from a
> > > particular person (account 32) so we may be able to speed up my
> example even
> > > more if we change the first statement of this query to read:
> > >
> > > CREATE TEMPORARY TABLE tmpLastStatusTimes SELECT
> > >     sl.`recipient_id`
> > >    ,MAX(sl.`time`) as lastmsg
> > > FROM status_log sl
> > > INNER JOIN traffic_log tl
> > >         on tl.`recipient_id` = sl.`recipient_id`
> > >         and tl.account_id = 32;
> > >
> > > That way we keep that table's contents within the scope of the actual
> > > desired results instead of computing the most recent statues for ALL
> > > messages for EVERYONE.
> > >
> > > Shawn Green
> > > Database Administrator
> > > Unimin Corporation - Spruce Pine
> >
> >
> >
> >
> > --
> > Sincerely,
> > Hadi Rastgou
> > <a href="http://www.spreadfirefox.com/?q=affiliates&amp;id=0&amp;t=1<http://www.spreadfirefox.com/?q=affiliates&id=0&t=1>
> ">Get
> > Firefox!</a>
>



--
Sincerely,
Hadi Rastgou
<a href="http://www.spreadfirefox.com/?q=affiliates&amp;id=0&amp;t=1">Get
Firefox!</a>
Thread
Query SpeedUnknown Sender1 Feb
  • Re: Query SpeedPeter Brawley1 Feb
  • Re: Query SpeedSGreen1 Feb
    • Re: Query SpeedUnknown Sender2 Feb
      • Re: Query SpeedUnknown Sender2 Feb
      • Re: Query SpeedSGreen2 Feb
        • Re: Query SpeedUnknown Sender3 Feb
          • Re: Query SpeedUnknown Sender8 Feb