Removes a user-defined function (UDF), so that it is not available for execution during Impala SELECT or INSERT operations.


DROP [AGGREGATE] FUNCTION [IF EXISTS] [db_name.]function_name(type[, type...])

Statement type: DDL

Usage notes:

Because the same function name could be overloaded with different argument signatures, you specify the argument types to identify the exact function to drop.


Currently, Impala UDFs and UDAs are not persisted in the metastore database. Information about these functions is held in the memory of the catalogd daemon. You must reload them by running the CREATE FUNCTION statements again each time you restart the catalogd daemon.

Cancellation: Cannot be cancelled.

HDFS permissions:

The user ID that the impalad daemon runs under, typically the impala user, does not need any particular HDFS permissions to perform this statement. All read and write operations are on the metastore database, not HDFS files and directories.

Related information:

Impala User-Defined Functions (UDFs), CREATE FUNCTION Statement