How do you define the Fill Factor when creating an index in MySql?
No.
http://dev.mysql.com/doc/refman/5.0/en/create-index.html
However, this is an “accepted” function request for version 6.x: http://bugs.mysql.com/bug.php?id=18178
So, do not hold your breath, seeing this soon.
Assuming you are using InnoDB, it looks like this is only supported at the database level, not at the index level.
innodb_fill_factor 100. https://dev.mysql.com/doc/refman/5.7/en/innodb-parameters.html#sysvar_innodb_fill_factor .
innodb_fill_factor
100