The EXTFNAPIV4_DESCRIBE_PARM_TABLE_HAS_REWIND attribute indicates if the parameter supports rewind. Used in a describe_parameter_set scenario.
a_sql_byte
Indicates whether a producer can support rewind. Valid only for table arguments.
You must also provide an implementation of the rewind table callback (_rewind_extfn() ), if you plan on setting DESCRIBE_PARM_TABLE_HAS_REWIND to true. The server cannot execute the UDF if you do not provide the callback method.
A UDF sets this property during the Optimization state if it can provide rewind capability for its result table at no cost. If it is expensive for the UDF to provide rewind, do not set this property, or set it to 0. If set to 0, the server provides rewind support.
On success, returns sizeof(a_sql_byte).