I'm currently doing a large number of REPLACE queries, I know that these evaluate as if doing a DELETE/INSERT pair, and I'm wondering if this is true on a disk io level as well with extra io occuring for the delete, and then re-insertion, vs what would occur with an UPDATE.
The way it works roughly each row gets updated around 12-24 times, the updated do not affect the primary key, or any of the other keys for that matter. The table is INNODB. So I'm thinking if the row is deleted then re-inserted, there is the overhead of one finding the old row and marking it deleted, two searching for the correct pos for the row in the table and in the key structures, and three writing the row to disk. Vs, and UPDATE would have the overhead of one finding the old row, and two writing the updates to disk. As such it seems like it actually be faster for me to attempt an UPDATE, and if it fails, then do an INSERT, rather than using REPLACE? Is this correct? -- John A. McCaskey Software Development Engineer Klir Technologies, Inc. [EMAIL PROTECTED] 206.902.2027 -- MySQL General Mailing List For list archives: http://lists.mysql.com/mysql To unsubscribe: http://lists.mysql.com/[EMAIL PROTECTED]
