Question

I would like to know if there is a difference in terms of performance between insert ignore and replace orders in MySQL.

I am using MySQL 5.0.31. All my tables are in InnoDB.

Answer 1

insert ignore – if key/row exists, skip insertion

replace – if key/row exists, delete the match row, and insert again

So, replace should be slower.
But insert ignore does not do the update

details : http://dev.mysql.com/doc/refman/5.5/en/replace.html

REPLACE works exactly like INSERT, except that if an old row in the table has the same value as a new row for a PRIMARY KEY or a UNIQUE index, the old row is deleted before the new row is inserted