[CALCITE-4189] Simplify 'p OR (p IS NOT TRUE)' to 'TRUE'

• Type: Improvement
• Status: Closed
• Priority: Minor
• Resolution: Fixed
• Fix Version/s: 1.36.0
• Labels: pull-request-available
• Assignee: hongyu guo
• Reporter: Thomas Rebele
• Created: 21/Aug/20 09:49
• Updated: 10/Nov/23 11:34
• Resolved: 03/Oct/23 10:30

Description

Statements of the form 'P OR P IS NOT TRUE' to 'TRUE' should always be true (please correct me if I am wrong):

> select x, X='A' as EQ, 
            X='A' IS NOT TRUE as EQ_NOT_TRUE,
            (X='A') OR ((X='A') IS NOT TRUE) as EQ_OR_EQ_NOT_TRUE
from (values 'A', 'B', null) as t(x);
+---+-------+-------------+-------------------+
| X |  EQ   | EQ_NOT_TRUE | EQ_OR_EQ_NOT_TRUE |
+---+-------+-------------+-------------------+
| A | true  | false       | true              |
| B | false | true        | true              |
|   |       | true        | true              |
+---+-------+-------------+-------------------+

Here a test case for the expected behavior:

@Test void testSimplifyPOrPNotTrue() {
  checkSimplify(
      and(
          vBool(),
          or(
              eq(vInt(), literal(1)),
              isNotTrue(eq(vInt(), literal(1)))
          )),
      "?0.bool0");
}

There are some other, similar expressions, such as 'P IS NOT FALSE OR NOT P', which can be reduced to true. Maybe there's a way to handle all of them?

Issue Links

• is duplicated by: CALCITE-5963 Simplify 'x OR NOT(x)' to TRUE
• links to: GitHub Pull Request #3416