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Zoltan Haindrich edited comment on CALCITE-2615 at 10/9/18 7:25 AM: -------------------------------------------------------------------- I went back to paper and proved to myself; how wrong I was :) ...my calculations were incorrect because predicates are not "anded" to the other conditions.. I propose to remove this simplifyOr-terms approach; but to retain most of the usefull simplification cases: I propose to only interpret cases like {{( f(A) || !f(A) )}} as true only if A is not nullable - and only consider nullable for IS predicates. was (Author: kgyrtkirk): I went back to paper and proved to myself; how wrong I was :) > When simplifying NOT-AND-OR, RexSimplify incorrectly applies predicates > deduced for operands to the same operands > ----------------------------------------------------------------------------------------------------------------- > > Key: CALCITE-2615 > URL: https://issues.apache.org/jira/browse/CALCITE-2615 > Project: Calcite > Issue Type: Task > Reporter: Julian Hyde > Assignee: Zoltan Haindrich > Priority: Major > Labels: newbie > > When simplifying NOT-AND-OR, RexSimplify incorrectly applies predicates > deduced for operands to the same operands. > Here is the test case (add it to RexProgramTest): > {code:java} > @Test public void testSimplifyNotAnd() { > final RexNode e = not( > and( > gt(and(vBool(1), literal(true)), > or(literal(true), literal(true), literal(false))), > gt(isNotNull(vBool(0)), eq(literal(false), vBool(1))), > or(ne(literal(true), literal(false)), > ge(vInt(0), literal((Integer) null))))); > final String expected = "TODO"; > checkSimplify(e, expected); > } > {code} > When you run it, verify will find a combination of assignments such that the > simplified expression returns a different result than the original. > The test case is not minimal; sorry. Maybe it reproduces with NOT-OR. > The bug is in > [RexSimplify.simplifyAndTerms|https://github.com/apache/calcite/blob/6b3844c0634792263a5073b8ea93565fb3415f41/core/src/main/java/org/apache/calcite/rex/RexSimplify.java#L412]. > Put a breakpoint at that line to see the problem. It passes through the > operands once, building a list of predicates. Then it passes through the > operands again, simplifying each operand. Thus operand1 is simplified using a > list of predicates that includes the predicate 'not operand1'. Clearly wrong. > [~kgyrtkirk], I warned that this was possible in our discussions. -- This message was sent by Atlassian JIRA (v7.6.3#76005)