Julian Hyde created CALCITE-4446: ------------------------------------ Summary: Implement three-valued logic for SEARCH operator Key: CALCITE-4446 URL: https://issues.apache.org/jira/browse/CALCITE-4446 Project: Calcite Issue Type: Bug Reporter: Julian Hyde
Implement three-valued logic for SEARCH operator. Consider the expression {{x IN (10, 20)}}, which we might represent as {{SEARCH(x, SARG(10, 20))}}. Suppose we invoke this with a value of {{NULL}} for {{x}}. Do we want it to return UNKNOWN, FALSE or TRUE? The answer is: all of the above. Here are the 3 variants: * {{SEARCH(10, 20, UNKNOWN AS TRUE)}}: {{x IS NULL OR x IN (10, 20)}} → TRUE * {{SEARCH(10, 20, UNKNOWN AS UNKNOWN)}}: {{x IN (10, 20)}} → UNKNOWN * {{SEARCH(10, 20, UNKNOWN AS FALSE)}}: {{x IS NOT NULL AND (x IN (10, 20))}} → FALSE Currently {{class Sarg}} has a field {{boolean containsNull}} which deals with the first two cases. Changing {{boolean containsNull}} to {{RexUnknownAs unknownAs}} (which has 3 values) will allow us to represent the third. The new representation is symmetrical under negation, which de Morgan's law suggests is a good thing. -- This message was sent by Atlassian Jira (v8.3.4#803005)