ALTER MASKING POLICY - ClickHouse Documentation

Modifies an existing masking policy. Syntax:

ALTER MASKING POLICY [IF EXISTS] policy_name ON [database.]table
    [UPDATE column1 = expression1 [, column2 = expression2 ...]]
    [WHERE condition]
    [TO {role1 [, role2 ...] | ALL | ALL EXCEPT role1 [, role2 ...]}]
    [PRIORITY priority_number]

All clauses are optional. Only the specified clauses will be updated. Part of: ALTER Related: CREATE MASKING POLICY, ALTER, SHOW

Last modified on August 25, 2026