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, [EMAIL PROTECTED] <[EMAIL PROTECTED]> wrote: > > > > سيد هادی راستگوی حقی <[EMAIL PROTECTED]> 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&id=0&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&id=0&t=1">Get Firefox!</a>