To disable compression, execute the ALTER table and specify ROW_FORMAT=DYNAMIC or ROW_FORMAT=COMPACT, followed by KEY_BLOCK_SIZE=0.
For example, if you do not want compression on the event_history table:
mysql> ALTER TABLE event_history ROW_FORMAT=DYNAMIC KEY_BLOCK_SIZE=0;Query OK, 0 rows affected (0.53 sec)Records: 0 Duplicates: 0 Warnings: 0