Heikki: Hi,
I would like to explain what is going on with the straight_join when it is used with my database. Suppose the command bellow: explain select table1 left join table2 on A=B left join table3 on C=D where ID = 1; When it is executed on one of our servers, mySql uses the right order for the search. It indicates the order Table1, table2 and table3, showing the indexes for each one. When it is executed on another of our servers, with the same database, but with another data, mySql indicates a non-optimized order for the search, and do not use the appropriated indexes, using sequential search. It can indicate, for example, table3, table1 and table2. To solve it I tried to modify the command, to use the straight_join, that is intended to force mySql to use the order I used to write the command: explain select STRAIGHT_JOIN table1 left join table2 on A=B left join table3 on C=D where ID = 1; But it got no success is this case. I'd already used it with success many times, but using it in this specific database and in this specific situation, the Straight_Join didn't work. I think it would be great if you could do something, because it can be a mySql bug, or innoDb bug instead. Because this, I sent to you an e-mail with the exact command I used and with the database I use. With that you will be able to reproduce the bug, as I could before sending it to you. Tuesday, March 2, 2004, 10:02:06 AM, você escreveu: ---------------[inicio]------------------ HT> Dyego, HT> http://www.mysql.com/doc/en/JOIN.html HT> LEFT JOIN means an 'outer join'. I think it does NOT force the join order. HT> STRAIGHT JOIN forces the join order. HT> Best regards, HT> Heikki HT> Innobase Oy HT> http://www.innodb.com HT> InnoDB - transactions, row level locking, and foreign keys for MySQL HT> InnoDB Hot Backup - a hot backup tool for InnoDB which also backs up MyISAM HT> tables ---------------[cortar]------------------ InnoDB,MySQL,SQL,Query ------------------------------------------------------------------------- ++ Dyego Souza Dantas Leal ++ Dep. Desenvolvimento ------------------------------------------------------------------------- E S C R I B A I N F O R M A T I C A ------------------------------------------------------------------------- The only stupid question is the unasked one (somewhere in Linux's HowTo) Linux registred user : #230601 -- ICQ : 1647350 $ look into "my eyes" Phone : +55 041 2106-1212 look: cannot open my eyes Fax : +55 041 296 -6640 ------------------------------------------------------------------------- Reply: [EMAIL PROTECTED] -- MySQL General Mailing List For list archives: http://lists.mysql.com/mysql To unsubscribe: http://lists.mysql.com/[EMAIL PROTECTED]
