MySql Index Fill Factor?

Question

How do you specify the Fill Factor when creating an index in MySql?

Answer 1

You don't.

http://dev.mysql.com/doc/refman/5.0/en/create-index.html

However, it is an 'accepted' feature request for version 6.x: http://bugs.mysql.com/bug.php?id=18178

So, don't hold your breath on seeing it any time soon.

Answer 2

Assuming that you are using InnoDB, it seems like this is only supported at database level, not index level.

The setting is called innodb_fill_factor and defaults to 100 see https://dev.mysql.com/doc/refman/5.7/en/innodb-parameters.html#sysvar_innodb_fill_factor for more details.