mysql's innodb_file_per_table tweak

If you use mysql's innodb table engine, you might find it useful to add the innodb_file_per_table option to your my.cnf file (under the [mysqld] section). This will create each innodb table in its own file/tablespace instead of putting everything in the ibdata file, thus making it easier for you to run optimize table faster. However, this option only affects new tables. Old tables would still live in the shared ibdata file.

Links: mySQL DBA has some further observations about this option and this is the mysql's manual page about this issue.