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  1. Apache Drill
  2. DRILL-6093

Unneeded columns in Drill logical project

    Details

    • Type: Bug
    • Status: Resolved
    • Priority: Major
    • Resolution: Fixed
    • Affects Version/s: 1.11.0, 1.12.0
    • Fix Version/s: 1.13.0
    • Component/s: None
    • Labels:

      Description

      Here is an example query with the corresponding logical plan. The project contains unnecessary columns L_ORDERKEY, O_ORDERKEY in the projection even when it is not required by subsequent operators e.g. DrillJoinRel.

      EXPLAIN PLAN without implementation FOR SELECT L.L_QUANTITY FROM cp.`tpch/lineitem.parquet` L, cp.`tpch/orders.parquet` O WHERE cast(L.L_ORDERKEY as int) = cast(O.O_ORDERKEY as int);

      ----------+

      | text | json |

      ----------+

      | DrillScreenRel

        DrillProjectRel(L_QUANTITY=[$1])

          DrillJoinRel(condition=[=($2, $4)], joinType=[inner])

            DrillProjectRel(L_ORDERKEY=[$0], L_QUANTITY=[$1], $f2=[CAST($0):INTEGER])

              DrillScanRel(table=[[cp, tpch/lineitem.parquet]], groupscan=[ParquetGroupScan [entries=[ReadEntryWithPath [path=classpath:/tpch/lineitem.parquet]], selectionRoot=classpath:/tpch/lineitem.parquet, numFiles=1, numRowGroups=1, usedMetadataFile=false, columns=[`L_ORDERKEY`, `L_QUANTITY`]]])

            DrillProjectRel(O_ORDERKEY=[$0], $f1=[CAST($0):INTEGER])

              DrillScanRel(table=[[cp, tpch/orders.parquet]], groupscan=[ParquetGroupScan [entries=[ReadEntryWithPath [path=classpath:/tpch/orders.parquet]], selectionRoot=classpath:/tpch/orders.parquet, numFiles=1, numRowGroups=1, usedMetadataFile=false, columns=[`O_ORDERKEY`]]])

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              • Assignee:
                gparai Gautam Kumar Parai
                Reporter:
                gparai Gautam Kumar Parai
                Reviewer:
                Aman Sinha
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                • Created:
                  Updated:
                  Resolved: