et-volatility-settings-table.md

Value Description
VOLATILE Repeated calls to the function with the same arguments always result in different values. Vertica always calls volatile functions for each invocation.
IMMUTABLE Calls to the function with the same arguments always results in the same return value.
STABLE Repeated calls to the function with the same arguments within the same statement returns the same output. For example, a function that returns the current user name is stable because the user cannot change within a statement. The user name could change between statements.
DEFAULT_VOLATILITY The default volatility. This is the same as VOLATILE.