Has Query optimizer improved in 5.4/5.5?

I am using MySQL 5.1.30 (MyISAM) and the query optimizer is quite bad at choosing the proper index. I often have to force it to use the correct index for Select statements, otherwise takes 50x to 100x slower than it should be. Has the query optiimizer improved any for later MySQL versions?

Re: Has Query optimizer improved in 5.4/5.5?

Mike, Has the query optiimizer improved any for later MySQL versions? Have a look at http://dev.mysql.com/tech-resources/articles/mysql-54.html. Peter Brawley http://www.artfulsoftware.com - mos wrote: I am using MySQL 5.1.30 (MyISAM) and the query optimizer is quite bad at choosing