The schema is SYSIBM.
The MAX_CARDINALITY function returns a value of type BIGINT representing the maximum number of elements that an array can contain. This is the cardinality that was specified in the CREATE TYPE statement for the ordinary array type.
The result can be null; if the argument is an associative array, the result is the null value.
SET LIST_SIZE = MAX_CARDINALITY(RECENT_CALLS)
The SQL variable LIST_SIZE is set
to 50, which is the maximum cardinality that the array type PHONENUMBERS was
defined with.