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Ruben Quesada Lopez edited comment on CALCITE-3198 at 7/15/19 10:24 AM: ------------------------------------------------------------------------ Same result is obtained with the following test, which is maybe more straightforward (and by solving this, the one in the description might be also solved as a side effect): {code} // query: select d.deptno from dept d where d.deptno<>7 or d.deptno=8 // plan before: LogicalProject(DEPTNO=[$0]) LogicalFilter(condition=[OR(<>($0, 7), <>($0, 8))]) LogicalTableScan(table=[[CATALOG, SALES, DEPT]]) // plan after (actual, unchanged): LogicalProject(DEPTNO=[$0]) LogicalFilter(condition=[OR(<>($0, 7), <>($0, 8))]) LogicalTableScan(table=[[CATALOG, SALES, DEPT]]) // plan after (expected, filter removed): LogicalProject(DEPTNO=[$0]) LogicalTableScan(table=[[CATALOG, SALES, DEPT]]) {code} was (Author: rubenql): Same result is obtained with the following test: {code} // query: select d.deptno from dept d where d.deptno<>7 or d.deptno=8 // plan before: LogicalProject(DEPTNO=[$0]) LogicalFilter(condition=[OR(<>($0, 7), <>($0, 8))]) LogicalTableScan(table=[[CATALOG, SALES, DEPT]]) // plan after (actual, unchanged): LogicalProject(DEPTNO=[$0]) LogicalFilter(condition=[OR(<>($0, 7), <>($0, 8))]) LogicalTableScan(table=[[CATALOG, SALES, DEPT]]) // plan after (expected, filter removed): LogicalProject(DEPTNO=[$0]) LogicalTableScan(table=[[CATALOG, SALES, DEPT]]) {code} > ReduceExpressionsRule.FILTER_INSTANCE does not reduce 'NOT(x=a AND x=b)' > ------------------------------------------------------------------------ > > Key: CALCITE-3198 > URL: https://issues.apache.org/jira/browse/CALCITE-3198 > Project: Calcite > Issue Type: Bug > Affects Versions: 1.20.0 > Reporter: Ruben Quesada Lopez > Priority: Minor > > Currently, ReduceExpressionsRule.FILTER_INSTANCE can successfully reduce a > query like this one (see RelOptRulesTest#testReduceConstantsDup): > {code} > // query: > select d.deptno from dept d where d.deptno=7 and d.deptno=8 > // plan before: > LogicalProject(DEPTNO=[$0]) > LogicalFilter(condition=[AND(=($0, 7), =($0, 8))]) > LogicalTableScan(table=[[CATALOG, SALES, DEPT]]) > // plan after: > LogicalProject(DEPTNO=[$0]) > LogicalValues(tuples=[[]]) > {code} > As we can see, since the filter is 'always false', the > LogicalTableScan+LogicalFilter are correctly replaced by an empty > LogicalValues. > However, the same filter with a NOT expression, is not correctly simplified: > {code} > // query: > select d.deptno from dept d where not(d.deptno=7 and d.deptno=8) > // plan before: > LogicalProject(DEPTNO=[$0]) > LogicalFilter(condition=[NOT(AND(=($0, 7), =($0, 8)))]) > LogicalTableScan(table=[[CATALOG, SALES, DEPT]]) > // plan after (actual, NOT distributivity for AND): > LogicalProject(DEPTNO=[$0]) > LogicalFilter(condition=[OR(<>($0, 7), <>($0, 8))]) > LogicalTableScan(table=[[CATALOG, SALES, DEPT]]) > // plan after (expected, filter removed): > LogicalProject(DEPTNO=[$0]) > LogicalTableScan(table=[[CATALOG, SALES, DEPT]]) > {code} > Since the filter is the negated of an 'always false filter' (the one used in > the previous query), it is therefore an 'always true filter', so the expected > behavior is that the LogicalFilter should be removed, and it is not. -- This message was sent by Atlassian JIRA (v7.6.14#76016)