Enabling innodb_fast_checksum will use more CPU-efficient algorithm, based on 4-byte words which can be beneficial for some workloads. Once enabled, turning it off will require table to be dump/imported again, since Percona Server will fail to start on data files created when innodb_fast_checksums was enabled.
In case you’ve migrated from Percona Server to MySQL you could get the “corrupted checksum” error message. In order to recover that table you’ll need to:
- Reinstall Percona Server to read your tables that were created with fast checksums.
- Dump the tables (or temporarily convert them to MyISAM).
- Install stock MySQL (or at least disable fast checksums).
- Restore the InnoDB tables (or convert back from MyISAM).
This is controlled by variable innodb_page_size. Changing the page size for an existing database is not supported. Table will need to be dumped/imported again if compatibility with MySQL is required.
Variable innodb_doublewrite_file provides an option to put the buffer on a dedicated disk in order to parallelize I/O activity on the buffer and on the tablespace. Only in case of crash recovery this variable cannot be changed, in all other cases it can be turned on/off without breaking the compatibility.
This feature has not been ported to Percona Server 5.6.