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https://issues.apache.org/jira/browse/CALCITE-5390?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=18035337#comment-18035337
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Dmitry Sysolyatin edited comment on CALCITE-5390 at 11/4/25 1:41 PM:
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That’s a good point about merging plans. I’ve started thinking more about this
problem and about [~zabetak]’s comment “I think there is an implicit
assumption that if there are multiple ids the scoping rules are more or less
the same with that of Java/C so the operators under a correlate will use the
one that is defined closer".
>From one hand, we can implement simple RexShuttle/RelShuttle which unify
>correlationId in the plan and apply such Shuttle after
>SubQueryRemoveRule.apply is called. Also the same approach can be used when we
>merge plans. For each plan we can apply such RexShuttle/RelShuttle. However,
>this only fixes the problem locally. If we say that the correlation ID must be
>unique, it should stay unique after every plan transformation. So, when
>transforming the plan, we need to make sure that the plan still has unique
>correlation IDs. This way, any code that runs after such transformations can
>rely on the fact that the correlation ID is unique (like
>RelDecorrelator/SqlImplementor which keep Map<CorrelationId, Value>)
On the other hand, if we follow [~zabetak]’s assumption and fix
RelDecorrelator/SqlImplementor, there may be other components, inside or
outside the Calcite codebase, that use the same approach. In that case, we need
some kind of safeguard to detect such situations and make the “implicit
assumption” explicit. However, I don’t have a clear idea of how to do that yet
was (Author: dmsysolyatin):
That’s a good point about merging plans. I’ve started thinking more about this
problem and about [~zabetak]’s comment “I think there is an implicit
assumption that if there are multiple ids the scoping rules are more or less
the same with that of Java/C so the operators under a correlate will use the
one that is defined closer".
>From one hand, we can implement simple RexShuttle/RelShuttle which unify
>correlationId in the plan and apply it after SubQueryRemoveRule.apply is
>called. Also the same approach can be used when we merge plans. For each plan
>we can apply such RexShuttle/RelShuttle. However, this only fixes the problem
>locally. If we say that the correlation ID must be unique, it should stay
>unique after every plan transformation. So, when transforming the plan, we
>need to make sure that the plan still has unique correlation IDs. This way,
>any code that runs after such transformations can rely on the fact that the
>correlation ID is unique (like RelDecorrelator/SqlImplementor which keep
>Map<CorrelationId, Value>)
On the other hand, if we follow [~zabetak]’s assumption and fix
RelDecorrelator/SqlImplementor, there may be other components, inside or
outside the Calcite codebase, that use the same approach. In that case, we need
some kind of safeguard to detect such situations and make the “implicit
assumption” explicit. However, I don’t have a clear idea of how to do that yet
> RelDecorrelator throws NullPointerException
> -------------------------------------------
>
> Key: CALCITE-5390
> URL: https://issues.apache.org/jira/browse/CALCITE-5390
> Project: Calcite
> Issue Type: Bug
> Components: core
> Reporter: Dmitry Sysolyatin
> Priority: Major
>
> The current query throws NullPointerException
> {code:java}
> SELECT
> (SELECT 1 FROM emp d WHERE d.job = a.job LIMIT 1) AS t1,
> (SELECT a.job = 'PRESIDENT' FROM emp s LIMIT 1) as t2
> FROM emp a;
> {code}
> Test case -
> [https://github.com/apache/calcite/commit/46fe9bc456f2d34cf7dccd29829c9e85abe69d5f]
> Logical plan before it fails:
> {code:java}
> LogicalProject(T1=[$8], T2=[$9])
> LogicalProject(EMPNO=[$0], ENAME=[$1], JOB=[$2], MGR=[$3], HIREDATE=[$4],
> SAL=[$5], COMM=[$6], DEPTNO=[$7], $f0=[$8], $f09=[$9])
> LogicalProject(EMPNO=[$0], ENAME=[$1], JOB=[$2], MGR=[$3], HIREDATE=[$4],
> SAL=[$5], COMM=[$6], DEPTNO=[$7], $f0=[$8], $f00=[$10])
> LogicalCorrelate(correlation=[$cor0], joinType=[left],
> requiredColumns=[{9}])
> LogicalProject(EMPNO=[$0], ENAME=[$1], JOB=[$2], MGR=[$3],
> HIREDATE=[$4], SAL=[$5], COMM=[$6], DEPTNO=[$7], $f0=[$8], $f9=[=($2,
> 'PRESIDENT')])
> LogicalCorrelate(correlation=[$cor0], joinType=[left],
> requiredColumns=[{2}])
> LogicalTableScan(table=[[scott, EMP]])
> LogicalAggregate(group=[{}], agg#0=[SINGLE_VALUE($0)])
> LogicalSort(fetch=[1])
> LogicalProject(EXPR$0=[1])
> LogicalFilter(condition=[=($2, $cor0.JOB)])
> LogicalTableScan(table=[[scott, EMP]])
> LogicalAggregate(group=[{}], agg#0=[SINGLE_VALUE($0)])
> LogicalSort(fetch=[1])
> LogicalProject(EXPR$0=[$cor0.$f9])
> LogicalTableScan(table=[[scott, EMP]]) {code}
> Stack trace:
> {code:java}
> Caused by: java.lang.NullPointerException
> at java.util.Objects.requireNonNull(Objects.java:203)
> at
> org.apache.calcite.sql2rel.RelDecorrelator.createValueGenerator(RelDecorrelator.java:833)
> at
> org.apache.calcite.sql2rel.RelDecorrelator.decorrelateInputWithValueGenerator(RelDecorrelator.java:1028)
> at
> org.apache.calcite.sql2rel.RelDecorrelator.decorrelateRel(RelDecorrelator.java:764)
> at
> org.apache.calcite.sql2rel.RelDecorrelator.decorrelateRel(RelDecorrelator.java:738)
> at sun.reflect.GeneratedMethodAccessor9.invoke(Unknown Source)
> at
> sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
> at java.lang.reflect.Method.invoke(Method.java:498)
> at org.apache.calcite.util.ReflectUtil$2.invoke(ReflectUtil.java:531)
> at
> org.apache.calcite.sql2rel.RelDecorrelator.getInvoke(RelDecorrelator.java:707)
> at
> org.apache.calcite.sql2rel.RelDecorrelator.decorrelateRel(RelDecorrelator.java:464)
> at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
> at
> sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
> at
> sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
> at java.lang.reflect.Method.invoke(Method.java:498)
> at org.apache.calcite.util.ReflectUtil$2.invoke(ReflectUtil.java:531)
> at
> org.apache.calcite.sql2rel.RelDecorrelator.getInvoke(RelDecorrelator.java:707)
> at
> org.apache.calcite.sql2rel.RelDecorrelator.decorrelateRel(RelDecorrelator.java:512)
> at
> org.apache.calcite.sql2rel.RelDecorrelator.decorrelateRel(RelDecorrelator.java:495)
> at sun.reflect.GeneratedMethodAccessor13.invoke(Unknown Source)
> at
> sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
> at java.lang.reflect.Method.invoke(Method.java:498)
> at org.apache.calcite.util.ReflectUtil$2.invoke(ReflectUtil.java:531)
> at
> org.apache.calcite.sql2rel.RelDecorrelator.getInvoke(RelDecorrelator.java:707)
> at
> org.apache.calcite.sql2rel.RelDecorrelator.decorrelateRel(RelDecorrelator.java:1187)
> at
> org.apache.calcite.sql2rel.RelDecorrelator.decorrelateRel(RelDecorrelator.java:1169)
> at sun.reflect.GeneratedMethodAccessor12.invoke(Unknown Source)
> at
> sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
> at java.lang.reflect.Method.invoke(Method.java:498)
> at org.apache.calcite.util.ReflectUtil$2.invoke(ReflectUtil.java:531)
> at
> org.apache.calcite.sql2rel.RelDecorrelator.getInvoke(RelDecorrelator.java:707)
> at
> org.apache.calcite.sql2rel.RelDecorrelator.decorrelateRel(RelDecorrelator.java:749)
> at
> org.apache.calcite.sql2rel.RelDecorrelator.decorrelateRel(RelDecorrelator.java:738)
> at sun.reflect.GeneratedMethodAccessor9.invoke(Unknown Source)
> at
> sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
> at java.lang.reflect.Method.invoke(Method.java:498)
> at org.apache.calcite.util.ReflectUtil$2.invoke(ReflectUtil.java:531)
> at
> org.apache.calcite.sql2rel.RelDecorrelator.getInvoke(RelDecorrelator.java:707)
> at
> org.apache.calcite.sql2rel.RelDecorrelator.decorrelateRel(RelDecorrelator.java:749)
> at
> org.apache.calcite.sql2rel.RelDecorrelator.decorrelateRel(RelDecorrelator.java:738)
> at sun.reflect.GeneratedMethodAccessor9.invoke(Unknown Source)
> at
> sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
> at java.lang.reflect.Method.invoke(Method.java:498)
> at org.apache.calcite.util.ReflectUtil$2.invoke(ReflectUtil.java:531)
> at
> org.apache.calcite.sql2rel.RelDecorrelator.getInvoke(RelDecorrelator.java:707)
> at
> org.apache.calcite.sql2rel.RelDecorrelator.decorrelateRel(RelDecorrelator.java:749)
> at
> org.apache.calcite.sql2rel.RelDecorrelator.decorrelateRel(RelDecorrelator.java:738)
> at sun.reflect.GeneratedMethodAccessor9.invoke(Unknown Source)
> at
> sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
> at java.lang.reflect.Method.invoke(Method.java:498)
> at org.apache.calcite.util.ReflectUtil$2.invoke(ReflectUtil.java:531)
> at
> org.apache.calcite.sql2rel.RelDecorrelator.getInvoke(RelDecorrelator.java:707)
> at
> org.apache.calcite.sql2rel.RelDecorrelator.decorrelate(RelDecorrelator.java:306)
> at
> org.apache.calcite.sql2rel.RelDecorrelator.decorrelateQuery(RelDecorrelator.java:230)
> at
> org.apache.calcite.tools.Programs$DecorrelateProgram.run(Programs.java:362)
> at
> org.apache.calcite.tools.Programs$SequenceProgram.run(Programs.java:337)
> at org.apache.calcite.prepare.Prepare.optimize(Prepare.java:177)
> at org.apache.calcite.prepare.Prepare.prepareSql(Prepare.java:312)
> at org.apache.calcite.prepare.Prepare.prepareSql(Prepare.java:220)
> at
> org.apache.calcite.prepare.CalcitePrepareImpl.prepare2_(CalcitePrepareImpl.java:648)
> at
> org.apache.calcite.prepare.CalcitePrepareImpl.prepare_(CalcitePrepareImpl.java:514)
> at
> org.apache.calcite.prepare.CalcitePrepareImpl.prepareSql(CalcitePrepareImpl.java:484)
> at
> org.apache.calcite.jdbc.CalciteConnectionImpl.parseQuery(CalciteConnectionImpl.java:236)
> at
> org.apache.calcite.jdbc.CalciteMetaImpl.prepareAndExecute(CalciteMetaImpl.java:623)
> at
> org.apache.calcite.avatica.AvaticaConnection.prepareAndExecuteInternal(AvaticaConnection.java:677)
> at
> org.apache.calcite.avatica.AvaticaStatement.executeInternal(AvaticaStatement.java:156)
> ... 10 more
> {code}
> UPD: other queries failing with same trace
> {code:sql}
> SELECT * FROM emps e WHERE e.name NOT IN (SELECT d.name FROM depts d WHERE
> e.deptno = d.deptno OR e.gender ='M');
> SELECT city
> FROM emps e
> WHERE ((CASE WHEN name NOT IN (SELECT name FROM sdepts s WHERE s.deptno =
> e.deptno) THEN '1' ELSE '2' END)
> NOT IN (SELECT name FROM depts d WHERE e.deptno = d.deptno));
> {code}
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