I recently came across a change that Percona Server implemented over normal MySQL InnoDB. The new feature is
XtraDB can use a more CPU-efficient algorithm, based on 4-byte words, which can be beneficial for some workloads (for instance write-heavy workloads on servers that can perform lots of IO).
Sounds good, but I wonder if there are any workloads in which this change would perform worse than the old method.
The documentation goes on to say:
The original algorithm is checked after the new one, so you can have data pages with old checksums and data pages with new checksums. However in this case, you may experience slow reads from pages having old checksums.
So, assuming that you enable
innodb_fast_checksum and rebuild all your InnoDB tables as suggested to remove the old checksums, are there any situations that the extra check on the old checksums would cause performance degradation?
In short, is there any reason not to run