It is now possible to build the server such that MyISAM tables can support up to 128 keys rather than the standard 64. This can be done by configuring the build using the option –with-max-indexes=N, where N≤128 is the maximum number of indexes to permit per table.
The server treats stored routine parameters and local variables (and stored function return values) according to standard SQL. Previously, parameters, variables, and return values were treated as items in expressions and were subject to automatic (silent) conversion and truncation. Now the data type is observed. Data type conversion and overflow problems that occur in assignments result in warnings, or errors in strict mode. The CHARACTER SET clause for character data type declarations is used. Parameters, variables, and return values must be scalars; it is no longer possible to assign a row value. Also, stored functions execute using the sql_mode value in force at function creation time rather than ignoring it.