Make a temp table, switch it in and out, and copy the last 30 days data into it.
#
# Make empty temp table
#
CREATE TABLE NOTIFICATION_NEW LIKE NOTIFICATION;
#
# Switch in new empty temp table
#
RENAME TABLE NOTIFICATION TO NOTIFICATION_OLD,NOTIFICATION_NEW TO NOTIFICATION;
#
# Retrieve last 30 days data
#
INSERT INTO NOTIFICATION SELECT * FROM NOTIFICATION_OLD
WHERE CreatedAt <>= DATE_SUB(CURDATE(), INTERVAL 30 dayDAY);
In your off hours, drop the old table
DROP TABLE NOTIFICATION_OLD;
Here are the Advantages to doing DELETEs like this
NOTIFICATION
is emptied fast by means switching in an empty table.NOTIFICATION
is immediately available for new INSERTs- The remaining 30 days are added back into
NOTIFICATION
while new INSERTs can take place. - Dropping the old version of
NOTIFICATION
does not interfere with new INSERTs - NOTE : I have recommended doing bait-and-switch for table DELETEs before : (See my July 19, 2012 post : Optimizing DELETE Query on MySQL MEMORY Table)
Give it a Try !!!