Retrieves the function library from the database metadata.
OrientDB SQL supports the use of functions and of user-defined functions. These are represented internally as
OFunction instances. They are stored at the database level in the function library, that is the
OFunctionLibrary. Using this method you can retrieve the function library from the database metadata, allowing you to operate on the available database functions or add new functions for your application to use.
This method returns an
OFunctionLibrary instance, which contains the database functions.