[jira] [Created] (CALCITE-4574) Wrong/Invalid plans when using RelBuilder#join with correlations

["Stamatis Zampetakis (Jira)" <ji...@apache.org>]

Stamatis Zampetakis created CALCITE-4574:
--------------------------------------------

             Summary: Wrong/Invalid plans when using RelBuilder#join with correlations
                 Key: CALCITE-4574
                 URL: https://issues.apache.org/jira/browse/CALCITE-4574
             Project: Calcite
          Issue Type: Bug
            Reporter: Stamatis Zampetakis
            Assignee: Stamatis Zampetakis
             Fix For: 1.27.0


RelBuilder#join produces wrong/invalid relational expressions when correlated variables are passed as a parameter along with different join types and non trivial (always true) conditions.

*Wrong plans* exist already in the code base where the {{requiredColumns}} attribute in {{LogicalCorrelate}} is missing some columns.

Consider for instance the middle plan in {{RelOptRulesTest#testSelectNotInCorrelated}}:
{noformat}
LogicalProject(SAL=[$5], EXPR$1=[IS NULL($10)])
  LogicalCorrelate(correlation=[$cor0], joinType=[left], requiredColumns=[{2}]) <-- PROBLEM
    LogicalTableScan(table=[[CATALOG, SALES, EMP]])
    LogicalFilter(condition=[=($cor0.EMPNO, $0)]) <-- $cor0.EMPNO refers to column 0 in EMP relation
      LogicalProject(DEPTNO=[$0], i=[true])
        LogicalFilter(condition=[=($cor0.JOB, $1)]) <-- $cor0.JOB refers to column 2 in EMP relation 
          LogicalTableScan(table=[[CATALOG, SALES, DEPT]])
{noformat}

{{EMPNO}} column (index 0) that is referenced in the correlation in the right input is not present in the {{requiredColumns}} attribute.

*Invalid plans* are created when the join type is SEMI or ANTI and the join condition uses columns from the right side. Currently, the join condition is added after the {{Correlate}} and columns from right side no longer exist thus the filter does not reference valid inputs. 
If we are lucky we will get an {{AssertionError}} when constructing the {{Filter}} operator:

{noformat}
RexInputRef index 8 out of range 0..7
java.lang.AssertionError: RexInputRef index 8 out of range 0..7
	at org.apache.calcite.util.Litmus$1.fail(Litmus.java:32)
	at org.apache.calcite.rex.RexChecker.visitInputRef(RexChecker.java:125)
	at org.apache.calcite.rex.RexChecker.visitInputRef(RexChecker.java:61)
	at org.apache.calcite.rex.RexInputRef.accept(RexInputRef.java:114)
	at org.apache.calcite.rex.RexChecker.visitCall(RexChecker.java:144)
	at org.apache.calcite.rex.RexChecker.visitCall(RexChecker.java:61)
	at org.apache.calcite.rex.RexCall.accept(RexCall.java:189)
	at org.apache.calcite.rel.core.Filter.isValid(Filter.java:127)
	at org.apache.calcite.rel.logical.LogicalFilter.<init>(LogicalFilter.java:72)
	at org.apache.calcite.rel.logical.LogicalFilter.create(LogicalFilter.java:116)
	at org.apache.calcite.rel.core.RelFactories$FilterFactoryImpl.createFilter(RelFactories.java:345)
	at org.apache.calcite.tools.RelBuilder.filter(RelBuilder.java:1349)
	at org.apache.calcite.tools.RelBuilder.filter(RelBuilder.java:1307)
	at org.apache.calcite.tools.RelBuilder.join(RelBuilder.java:2407)
{noformat}

otherwise (assertions disabled) we will end up with an invalid plan.

{code:java}
RelNode root = builder
        .scan("EMP")
        .variable(v)
        .scan("DEPT")
        .join(type,
            builder.equals(
                builder.field(2, 0, "DEPTNO"),
                builder.field(2, 1, "DEPTNO")), ImmutableSet.of(v.get().id))
        .build();
{code}

+Actual plan+
{noformat}
LogicalFilter(condition=[=($7, $8)]) <- PROBLEM I
  LogicalCorrelate(correlation=[$cor0], joinType=[semi], requiredColumns=[{}]) <- PROBLEM II
    LogicalTableScan(table=[[scott, EMP]])
    LogicalTableScan(table=[[scott, DEPT]])
{noformat}

+Expected plan+
{noformat}
LogicalCorrelate(correlation=[$cor0], joinType=[semi], requiredColumns=[{7}])
  LogicalTableScan(table=[[scott, EMP]])
  LogicalFilter(condition=[=($cor0.DEPTNO, $0)])
    LogicalTableScan(table=[[scott, DEPT]])
{noformat}




--
This message was sent by Atlassian Jira
(v8.3.4#803005)