The image predicatetable.gif shows the conceptual structure of an internal (predicate) table that captures the predicate information for the expression set.
There are three rows and five columns in the conceptual predicate table.
The first column is labeled Rid, which is the identifier of the row storing the expression in the CONSUMER table.
The second column is labeled G1 (predicate group 1), and it contains two subcolumns. The subcolumns are Op, which is short for operator, and RHS, which is short for the constant on the right-hand side of the predicate.
The third column is labeled G2 (predicate group 2), and it contains two subcolumns. The subcolumns are Op, which is short for operator, and RHS, which is short for the constant on the right-hand side of the predicate.
The fourth column is labeled G3 (predicate group 3), and it contains two subcolumns. The subcolumns are Op, which is short for operator, and RHS, which is short for the constant on the right-hand side of the predicate.
The last column is labeled Sparse_predicate.
The information in row 1 is as follows:
Rid is r1.
G1 operator is equals to (=).
G1 RHS is Taurus.
G2 operator is less than (<).
G2 RHS is 15000.
G3 operator and G3 RHS are null.
Sparse predicate is Mileage < 25000.
The information in row 2 is as follows:
Rid is r2.
G1 operator is equals to (=).
G1 RHS is Mustang.
G2 operator is less than (<).
G2 RHS is 20000.
G3 operator and G3 RHS are null.
Sparse predicate is Year > 1999.
The information in row 3 is as follows:
Rid is r3.
G1 operator is null.
G1 RHS is null.
G2 operator is less than (<).
G2 RHS is 20000.
G3 operator is greater than (>).
G3 RHS is 200.
Sparse predicate is null.