Supported database products include:
The set of Supported Database products is predetermined and cannot be modified. Refer to the Supported Platforms document for the current versions supported.
The database products supported in a partition determine the limits and restrictions applied to database objects. For example, the field lengths supported vary by database type. Consequently, if you create a field any warning messages relating to the maximum allowable length of a field will relate directly to the supported database products.
MySQL Database note:
By default, MySQL max index key length for a single column is 767 bytes.
This limit can be increased by setting these system variables:
'innodb_file_format'=Barracuda
'innodb_file_format_max'=Barracuda
'innodb_large_prefix'=ON.
'sql_mode'=<existing values>,PAD_CHAR_TO_FULL_LENGTH (note comma as the delimiter)
Refer to the MySQL online documentation for details.