[CALCITE-3500] Validator infers incorrect type for "IS NOT DISTINCT FROM"

• Type: Bug
• Status: Open
• Priority: Major
• Resolution: Unresolved
• Assignee: Unassigned
• Reporter: Julian Hyde
• Created: 13/Nov/19 21:39
• Updated: 14/Nov/19 19:06

Description

Validator infers incorrect type for "IS NOT DISTINCT FROM". I got the following output from a test:

[INFO] Running org.apache.calcite.test.fuzzer.RexProgramFuzzyTest
2019-11-13 13:30:16,459 [pool-1-thread-3] INFO  - Using seed 44 for rex fuzzing
2019-11-13 13:30:19,869 [pool-1-thread-3] INFO  - Rex fuzzing results: number of cases tested=2000, failed cases=0, duplicate failures=0, fuzz rate=586 per second
Shrinked to 36669 chars, time remaining 19997
Shrinked to 9704 chars, time remaining 19996
Shrinked to 9631 chars, time remaining 19993
Shrinked to 9287 chars, time remaining 19992
Shrinked to 7058 chars, time remaining 19989
Shrinked to 6507 chars, time remaining 19986
Shrinked to 5317 chars, time remaining 19985
Shrinked to 5191 chars, time remaining 19985
Shrinked to 4990 chars, time remaining 19984
Shrinked to 4844 chars, time remaining 19984
Shrinked to 3877 chars, time remaining 19981
Shrinked to 3628 chars, time remaining 19981
Shrinked to 275 chars, time remaining 19980
Shrinked to 258 chars, time remaining 19980
Shrinked to 239 chars, time remaining 19980
Shrinked to 188 chars, time remaining 19979
2019-11-13 13:30:20,616 [pool-1-thread-1] INFO  - Rex fuzzing results: number of cases tested=406, failed cases=1, duplicate failures=0, fuzz rate=100 per second
2019-11-13 13:30:20,617 [pool-1-thread-1] INFO  - Randomized test identified a potential defect. Feel free to fix that issue
java.lang.IllegalStateException: Unable to simplify unknownAsFalse<(IS NOT DISTINCT FROM(>(+(CAST(0):INTEGER), +(0)), true), true)
lt(isNotDistinctFrom(gt(unaryPlus(abstractCast(literal(0), tInt(true))), unaryPlus(literal(0))), trueLiteral), trueLiteral)
	at org.apache.calcite.test.fuzzer.RexProgramFuzzyTest.checkUnknownAs(RexProgramFuzzyTest.java:228)
	at org.apache.calcite.test.fuzzer.RexProgramFuzzyTest.checkUnknownAsAndShrink(RexProgramFuzzyTest.java:209)
	at org.apache.calcite.test.fuzzer.RexProgramFuzzyTest.checkUnknownAs(RexProgramFuzzyTest.java:172)
	at org.apache.calcite.test.fuzzer.RexProgramFuzzyTest.generateRexAndCheckTrueFalse(RexProgramFuzzyTest.java:462)
	Suppressed: org.apache.calcite.test.fuzzer.RexProgramFuzzyTest$1: seed -104518976443406885
Caused by: java.lang.AssertionError
	at org.apache.calcite.rex.RexSimplify.validateStrongPolicy(RexSimplify.java:843)
	at org.apache.calcite.rex.RexSimplify.simplifyIs2(RexSimplify.java:682)
	at org.apache.calcite.rex.RexSimplify.simplifyIs(RexSimplify.java:653)
	at org.apache.calcite.rex.RexSimplify.simplify(RexSimplify.java:281)

I believe that it means that a particular call to IS NOT DISTINCT FROM has a not-null return and has nullable arguments and this contradict's the Strong.ANY policy. I suspect that the policy for that operator should not be Strong.ANY.

Discovered by the validateStrongPolicy method added in CALCITE-3457.

Issue Links

• is related to: CALCITE-3457 RexSimplify incorrectly simplifies IS NOT NULL operator with ITEM call