1. Generally reducing fragmentation in the data/index files will reduce the footprint of tables on disk, and can be more efficient to query. With innodb you need to be using the innodb-file-per-table option, and then you can use OPTIMIZE TABLE table; to rebuild it. You don't get detailed progress like with myisamchk, but that's not important anyway. You can estimate how long it will take by keeping track of how long any given ALTER / OPTIMIZE takes in GB/hr.
2. Don't stare at the screen. Start it, script the process & have it email your phone when it's done. Do something else in the mean time. 3. Yes, innodb table will take more space on disk. If you have a really long primary key, and lots of secondary indexes, then it can take a *lot* more. Disk is cheap, don't worry about it. Regards, Gavin Towey -----Original Message----- From: Hank [mailto:hes...@gmail.com] Sent: Tuesday, September 28, 2010 3:29 PM To: mysql@lists.mysql.com Subject: Migrating my mindset from MyISAM to InnoDB Primarily due to many positive posts I've seen about MySQL 5.5 and advances in InnoDB, I'm seriously considering converting all my MyISAM databases to InnoDB. I don't need many of the InnoDB features, but if I'm going to upgrade from 4.1.14 to 5.5, I might as well bit the bullet since that seems to be the direction of MySQL/Oracle. I've been using MySQL 4.1.14 for years in my production environment, including one master and several slaves for report and long running queries. Every 6 to 12 months the master MYI index files grow fairly large, so I take the production database offline, and run myisamchk -r on the index files to rebuild them and shrink them back down again. I usually get a 20% to 30% space saving and improved performance after the rebuilds. This has worked very well for me for, well, almost 10 years now! And when I say "large" my two main tables have about 200 million rows, and the myisamchk can take between 60-160 minutes to complete. I very much like how verbose myisamchk is in detailing which index it is currently rebuilding, and the progress in terms of records re-indexed. SO, my questions are this: 1. With InnoDB, do the indexes ever need to be rebuilt to reduce index size and improve performance like I get with MyISAM? 2. If so, are there any tools like myisamchk to monitor the InnoDB index rebuild process, other than issuing a "repair table..." and staring indefinitely at a blank screen until it finishes hours later? 3. I've been testing the rebuild process during upgrading using "alter table <table_name> engine=innodb" to convert my tables from 4.1.14 to 5.5.6, and I'm seeing a 130% increase (more than double) in the raw disk space required for the new InnoDB tables compared to their old MyISAM counterparts. (I am using single-file-per-table). Is this normal? If not, how can I adjust the space requirements for these tables so they don't take up so much additional space? I'm sure I'll have more questions later, but many thanks for your comments and thoughts. -Hank -- MySQL General Mailing List For list archives: http://lists.mysql.com/mysql To unsubscribe: http://lists.mysql.com/mysql?unsub=gto...@ffn.com This message contains confidential information and is intended only for the individual named. If you are not the named addressee, you are notified that reviewing, disseminating, disclosing, copying or distributing this e-mail is strictly prohibited. Please notify the sender immediately by e-mail if you have received this e-mail by mistake and delete this e-mail from your system. E-mail transmission cannot be guaranteed to be secure or error-free as information could be intercepted, corrupted, lost, destroyed, arrive late or incomplete, or contain viruses. The sender therefore does not accept liability for any loss or damage caused by viruses or errors or omissions in the contents of this message, which arise as a result of e-mail transmission. [FriendFinder Networks, Inc., 220 Humbolt court, Sunnyvale, CA 94089, USA, FriendFinder.com -- MySQL General Mailing List For list archives: http://lists.mysql.com/mysql To unsubscribe: http://lists.mysql.com/mysql?unsub=arch...@jab.org
