
 Description
 
 Takes a raw file path, and attempts to extract the schema name from it.
 
 Useful for when interacting with Performance Schema data 
 concerning IO statistics, for example.
 
 Currently relies on the fact that a table data file will be within a 
 specified database directory (will not work with partitions or tables
 that specify an individual DATA_DIRECTORY).
 
 Parameters
 
 path (VARCHAR(512)):
 The full file path to a data file to extract the schema name from.
 
 Returns
 
 VARCHAR(64)
 
 Example
 
 mysql> SELECT sys.extract_schema_from_file_name('/var/lib/mysql/employees/employee.ibd');
 +----------------------------------------------------------------------------+
 | sys.extract_schema_from_file_name('/var/lib/mysql/employees/employee.ibd') |
 +----------------------------------------------------------------------------+
 | employees                                                                  |
 +----------------------------------------------------------------------------+
 1 row in set (0.00 sec)
 