In Impala 2.9 and higher, you can run the REFRESH
FUNCTIONS statement to refresh the user-defined functions (UDFs) created outside
of Impala. For example, you can add Java-based UDFs to the metastore database through the
Hive CREATE FUNCTION statements and make those UDFs visible to Impala at
the database level by subsequently running REFRESH FUNCTIONS.
The REFRESH FUNCTIONS statement is only required if you create or modify
UDFs from outside of Impala. Updated metadata, as a result of running REFRESH
FUNCTIONS, is broadcast to all Impala coordinators.
Once issued, the REFRESH FUNCTIONS statement cannot be cancelled.
Syntax:
REFRESH FUNCTIONS
db_name