The world's most popular open source database
Functionality added or changed:
Incompatible Change:
The number of function names affected by
IGNORE_SPACE was reduced significantly in
MySQL 5.1.13, from about 200 to about 30. (For details about
IGNORE_SPACE, see
Function Name Parsing and Resolution.) This change improves the
consistency of parser operation. However, it also introduces the
possibility of incompatibility for old SQL code that relies on
the following conditions:
IGNORE_SPACE is disabled.
The presence or absence of whitespace following a function
name is used to distinguish between a built-in function and
stored function that have the same name (for example,
PI() versus PI
()).
For functions that are no longer affected by
IGNORE_SPACE as of MySQL 5.1.13, that
strategy no longer works. Either of the following approaches can
be used if you have code that is subject to the preceding
incompatibility:
If a stored function has a name that conflicts with a
built-in function, refer to the stored function with a
schema name qualifier, regardless of whether whitespace is
present. For example, write
or
schema_name.PI().
schema_name.PI
()
Alternatively, rename the stored function to use a non-conflicting name and change invocations of the function to use the new name.
Incompatible Change:
The innodb_buffer_pool_awe_mem_mb system
variable has been removed and should no longer be used.

