[jira] [Updated] (CALCITE-891) TableScan without Project cannot be substituted by any projected materialization

["Maryann Xue (JIRA)" <ji...@apache.org>]

     [ https://issues.apache.org/jira/browse/CALCITE-891?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]

Maryann Xue updated CALCITE-891:
--------------------------------
    Attachment: CALCITE-891_2.patch

[~julianhyde] Could you please review this patch?

> TableScan without Project cannot be substituted by any projected materialization
> --------------------------------------------------------------------------------
>
>                 Key: CALCITE-891
>                 URL: https://issues.apache.org/jira/browse/CALCITE-891
>             Project: Calcite
>          Issue Type: Bug
>            Reporter: Maryann Xue
>            Assignee: Julian Hyde
>            Priority: Minor
>         Attachments: CALCITE-891_2.patch
>
>
> A TableScan that does not have a Project as its parent cannot be matched by any UnifyRules and thus cannot be substituted by a projected materialization; while the same TableScan with an identity projection could.
> {code}
>   @Test public void testJoinMaterialization2() {
>     String q = "select *\n"
>             + "from \"emps\"\n"
>             + "join \"depts\" using (\"deptno\")";
>     checkMaterialize("select \"deptno\", \"empid\", \"name\", \"salary\", \"commission\" from \"emps\"", q);
>   }
> {code}
> In the above test case, the initial Rel was like:
> {code}
> LogicalProject(...)
>   LogicalJoin(...)
>     TableScan(table=[[hr, emps]])
>     TableScan(table=[[hr, depts]])
> {code}
> And the queryDescendent {{TableScan(table=\[\[hr, emps\]\])}} cannot be matched by any UnifyRules that could have matched {{LogicalProject(<identity_project_list>, TableScan(table=\[\[hr, emps\]\]))}}.
> The following changes would make this test case pass. Not sure if this would be the best fix, but it is at least a good illustration of the problem.
> {code}
> diff --git a/core/src/main/java/org/apache/calcite/plan/RelOptUtil.java b/core/src/main/java/org/apache/calcite/plan/RelOptUtil.java
> index 7762bf7..ccece75 100644
> --- a/core/src/main/java/org/apache/calcite/plan/RelOptUtil.java
> +++ b/core/src/main/java/org/apache/calcite/plan/RelOptUtil.java
> @@ -2861,9 +2861,6 @@ public static RelNode permute(
>    public static RelNode createProject(final RelFactories.ProjectFactory factory,
>        final RelNode child, final List<Integer> posList) {
>      RelDataType rowType = child.getRowType();
> -    if (Mappings.isIdentity(posList, rowType.getFieldCount())) {
> -      return child;
> -    }
>      final List<String> fieldNames = rowType.getFieldNames();
>      final RexBuilder rexBuilder = child.getCluster().getRexBuilder();
>      return factory.createProject(child,
> diff --git a/core/src/main/java/org/apache/calcite/sql2rel/SqlToRelConverter.java b/core/src/main/java/org/apache/calcite/sql2rel/SqlToRelConverter.java
> index 50f22c1..b0a519a 100644
> --- a/core/src/main/java/org/apache/calcite/sql2rel/SqlToRelConverter.java
> +++ b/core/src/main/java/org/apache/calcite/sql2rel/SqlToRelConverter.java
> @@ -2240,6 +2240,8 @@ protected RelNode createJoin(
>        }
>      }
> +    leftRel = leftRel instanceof Project ? leftRel : RelOptUtil.createProject(leftRel, ImmutableIntList.identity(leftRel.getRowType().getFieldCount()));
> +    rightRel = rightRel instanceof Project ? rightRel : RelOptUtil.createProject(rightRel, ImmutableIntList.identity(rightRel.getRowType().getFieldCount()));
>      final Join originalJoin =
>          (Join) RelFactories.DEFAULT_JOIN_FACTORY.createJoin(leftRel, rightRel,
>              joinCond, joinType, ImmutableSet.<String>of(), false);
> {code}



--
This message was sent by Atlassian JIRA
(v6.3.4#6332)