Due to MSI restrictions, the MSI packages of MySQL 5.5.25a will
treat the version as 5.5.26 internally; for example, as
displayed by the Installation Wizard. MySQL itself reports the
version as 5.5.25a; for example, if you check the value of the
VERSION() SQL function or the
version system variable.
A regression bug in the optimizer could cause excessive disk
InnoDB tables. For
tables created with
OPTIMIZE TABLE can be
used to recover excessive space used. For tables created in the
InnoDB system tablespace,it is
necessary to perform a dump and restore into a new instance of
the system tablespace.
(Bug #65745, Bug #14248833)