[CALCITE-2257] Combination of predicates can be proved to be always true

• Type: Improvement
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 1.16.0
• Fix Version/s: 1.17.0
• Component/s: core
• Labels: filter pull-request-available
• Assignee: Vitalii Diravka
• Reporter: Vitalii Diravka
• Created: 15/Apr/18 17:33
• Updated: 29/Apr/19 17:14
• Resolved: 01/Mar/19 13:39

Description

I have found the case, when Filter operator is not necessary since filter condition is always true, but that is not detected by current version of Calcite.

select SAL from EMPNULLABLES_20 where SAL IS NOT NULL OR SAL is null

LogicalProject(SAL=[$5])
  LogicalFilter(condition=[OR(IS NOT NULL($5), IS NULL($5))])
    LogicalProject(EMPNO=[$0], ENAME=[$1], JOB=[$2], MGR=[$3], HIREDATE=[$4], SAL=[$5], COMM=[$6], SLACKER=[$8])
      LogicalFilter(condition=[AND(=($7, 20), >($5, 1000))])
        LogicalTableScan(table=[[CATALOG, SALES, EMPNULLABLES]])

But filter condition OR(IS NOT NULL($5), IS NULL($5)) can be proved to be always true.
I have tried ReduceExpressionsRule, but it doesn't give effect.

Issue Links

• is related to: CALCITE-2247 Simplify AND and OR conditions using predicates
• relates to: CALCITE-2438 RexCall#isAlwaysTrue return incorrect result
• relates to: CALCITE-1995 Remove predicates from Filter if they can be proved to be always true or false
• relates to: DRILL-6173 Support transitive closure during filter push down and partition pruning
• links to: GitHub Pull Request #666
• links to: PR-666