Mixed Operators

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The following list describes the mixed operators.

DBOP_in

Membership test of a scalar or row in a table. Inputs for this operator are a row and a table; it produces a Boolean result as output.

DBOP_exists, DBOP_unique

These operators take a table T as input and produce a Boolean result as output. DBOP_exists evaluates to TRUE if the cardinality of T is greater than zero; otherwise it evaluates to FALSE. DBOP_unique detects duplicate rows in T. If any two rows in T are equal to one another, DBOP_unique evaluates to FALSE; otherwise, it evaluates to TRUE.

DBOP_subset, DBOP_proper_subset, DBOP_superset, DBOP_proper_superset, DBOP_disjoint,

These operators take two tables T1 and T2 as input and determine whether T1 is a subset, proper_subset, superset, proper_superset, or disjoint set of T2. The output is Boolean.