MySQL 5.6 Reference Manual Including MySQL NDB Cluster 7.3-7.4 Reference Guide
The mysql.func system table shows which UDFs
have been registered using CREATE
FUNCTION:
SELECT * FROM mysql.func;
The func table has these columns:
name
The UDF name as referred to in SQL statements.
ret
The UDF return value type. Permitted values are 0
(STRING), 1 (REAL), 2
(INTEGER), 3 (ROW), or 4
(DECIMAL).
dl
The name of the UDF library file containing the executable UDF
code. The file is located in the directory named by the
plugin_dir system variable.
type
The UDF type, either function (scalar) or
aggregate.