[CALCITE-1497] Infer IS NOT NULL, and project predicates

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 1.11.0
• Assignee: Julian Hyde
• Reporter: Julian Hyde
• Created: 19/Nov/16 02:36
• Updated: 06/Jan/17 19:30
• Resolved: 20/Nov/16 22:46

Description

RexImplicationChecker makes some mistakes when OR is on the left-hand size or AND is on the right-hand side. The following 3 tests should all succeed, but all currently give the wrong result. I intend to check in the tests with my fix for CALCITE-1483 (coming soon, currently in my branch https://github.com/julianhyde/calcite/tree/1483-not-in-not-null).

    // "s is not null or i = 5" does not imply "s is not null"
    f.checkNotImplies(f.or(sIsNotNull, iEq5), sIsNotNull);

    // "s is not null" implies "s is not null or i = 5"
    f.checkImplies(sIsNotNull, f.or(sIsNotNull, iEq5));

    // "s is not null" implies "i = 5 or s is not null"
    f.checkImplies(sIsNotNull, f.or(iEq5, sIsNotNull));

amargoor, Can you comment on these?