how to drop partition without dropping data in MySQL?

Question

I have a table like:

create table registrations( 
id int not null auto_increment primary key,
name varchar(50),
mobile_number varchar(13)) 
engine=innodb 
partit         


        

Answer 1

You can reorganize the partition p0 using the ALTER TABLE .. REORGANIZE PARTITION command.

http://dev.mysql.com/doc/refman/5.5/en/partitioning-management-range-list.html

If you intend to change the partitioning of a table without losing data, use ALTER TABLE ... REORGANIZE PARTITION

ALTER TABLE registrations 
REORGANIZE PARTITION p0 INTO (
    PARTITION p0 VALUES LESS THAN (10000),
    PARTITION p0 VALUES LESS THAN (20000)
);

Note that this will not make sense until you actually create several partitions e.g.

ALTER TABLE registrations 
REORGANIZE PARTITION p0 INTO (
    PARTITION p0 VALUES LESS THAN (10000),
    PARTITION p1 VALUES LESS THAN (20000),
    PARTITION p2 VALUES LESS THAN MAXVALUE
);

Have a look at RANGE partitioning in MySQL

If your partition p2 is becoming too large you can split it the same way.