[
https://issues.apache.org/jira/browse/CALCITE-3198?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
]
Ruben Quesada Lopez updated CALCITE-3198:
-----------------------------------------
Summary: Enhance RexSimplify to handle (x<>a or x<>b) (was:
ReduceExpressionsRule.FILTER_INSTANCE does not reduce 'NOT(x=a AND x=b)')
> Enhance RexSimplify to handle (x<>a or x<>b)
> --------------------------------------------
>
> Key: CALCITE-3198
> URL: https://issues.apache.org/jira/browse/CALCITE-3198
> Project: Calcite
> Issue Type: Improvement
> Affects Versions: 1.20.0
> Reporter: Ruben Quesada Lopez
> Assignee: Ruben Quesada Lopez
> Priority: Minor
> Labels: pull-request-available
> Fix For: 1.21.0
>
> Time Spent: 6h 40m
> Remaining Estimate: 0h
>
> 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, when $0's type is NOT nullable, filter removed):
> LogicalProject(DEPTNO=[$0])
> LogicalTableScan(table=[[CATALOG, SALES, DEPT]])
> // plan after (expected, when $0's type IS nullable, filter simplified as IS
> NOT NULL):
> LogicalProject(DEPTNO=[$0])
> LogicalFilter(condition=[IS NOT NULL($0)])
> LogicalTableScan(table=[[CATALOG, SALES, DEPT]])
> {code}
--
This message was sent by Atlassian JIRA
(v7.6.14#76016)
