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How to optimize a MySQL table after deleting some rows?
Use the OPTIMIZE TABLE command to optimize a MySQL table −
optimize table yourTableName;
Let us first create a table −
mysql> create table DemoTable( Id int NOT NULL AUTO_INCREMENT PRIMARY KEY, Name varchar(100) ); Query OK, 0 rows affected (1.38 sec)
Insert some records in the table using insert command −
mysql> insert into DemoTable(Name) values('Chris');
Query OK, 1 row affected (0.27 sec)
mysql> insert into DemoTable(Name) values('Robert');
Query OK, 1 row affected (0.15 sec)
mysql> insert into DemoTable(Name) values('Bob');
Query OK, 1 row affected (0.22 sec)
mysql> insert into DemoTable(Name) values('David');
Query OK, 1 row affected (0.38 sec)Display all records from the table using select statement −
mysql> select *from DemoTable;
This will produce the following output −
+----+--------+ | Id | Name | +----+--------+ | 1 | Chris | | 2 | Robert | | 3 | Bob | | 4 | David | +----+--------+ 4 rows in set (0.00 sec)
Now let us delete rows from the table −
mysql> delete from DemoTable where Id IN(1,3); Query OK, 2 rows affected (0.29 sec) mysql> select *from DemoTable; +----+--------+ | Id | Name | +----+--------+ | 2 | Robert | | 4 | David | +----+--------+ 2 rows in set (0.00 sec)
Following is the query to optimize the table created above and after deleting some rows −
mysql> optimize table DemoTable;
This will produce the following output −
+------------------+----------+----------+-------------------------------------------------------------------+ | Table | Op | Msg_type | Msg_text | +------------------+----------+----------+-------------------------------------------------------------------+ | web.DemoTable | optimize | note | Table does not support optimize, doing recreate + analyze instead | | web.DemoTable | optimize | status | OK | +------------------+----------+----------+-------------------------------------------------------------------+ 2 rows in set (4.32 sec)
Updated on: 03-Sep-2019
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