The schema for the tpf_blob procedure is dynamic.
The data types for column s in the result set and input table can be one of VARCHAR, BINARY, LONG VARCHAR, or LONG BINARY. You accomplish this using the describe_column_get method of a_v4_extfn_proc_context to get the data type of the input table column. The implementation of the TPF is adjusted according to what the actual defined schema is. The interpretation of the pattern argument of the procedure differs depending on the data type of column s. For character data types, the argument is interpreted as a letter; for binary data types it is interpreted as a digit.