Mysql releases space. mysql releases space.

Mysql releases space. mysql releases space.
Mysql releases Space
Some tables in the production system use delete to delete some rows and the space is not released.
Cause: similar to the high-water line production principle of Oracle
Solution:

Method 1:

Execute the optimize table name;

Note:
1. optimize table only applies to MyISAM, BDB, and InnoDB tables;
2. optimize table will generate a lock, and it is recommended to execute it when the business is low;
3. For tables with frequent DDL operations, regularly execute OPTIMIZE TABLE

Method 2:

Write an SQL statement to create a new table, delete the old table, and rename the new table;

Old_tables create new_table;

Truncate table old_tables;
Rename new_tables to old_tables.