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  1. Apache Drill
  2. DRILL-1309

Projected columns are not pushed into scan

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    Details

    • Type: Bug
    • Status: Resolved
    • Priority: Major
    • Resolution: Fixed
    • Affects Version/s: None
    • Fix Version/s: 0.5.0
    • Component/s: None
    • Labels:
      None

      Description

      While performing the following query on two text files, the projected column does not get pushed into the scan.

      explain plan for select t1.columns[1] from dfs.`/tmp/t1.csv` t1, dfs.`/tmp/t2.csv` t2 where t1.columns[0] = t2.columns[0];

      00-00 Screen
      00-01 Project(EXPR$0=[ITEM($0, 1)])
      00-02 HashJoin(condition=[=($1, $2)], joinType=[inner])
      00-04 Project(columns=[$0], $f2=[ITEM($0, 0)])
      00-06 Scan(groupscan=[EasyGroupScan [selectionRoot=/tmp/t1.csv, columns = [SchemaPath [`columns`], SchemaPath [`columns`[0]]]]])
      00-03 Project($f20=[$0])
      00-05 Project($f2=[ITEM($0, 0)])
      00-07 Scan(groupscan=[EasyGroupScan [selectionRoot=/tmp/t2.csv, columns = [SchemaPath [`columns`[0]]]]])

      In the above plan (00-06) we see that the scan contains the following column projections pushed into scan: 'columns' and 'columns[0]'.

      We should not push 'columns' into the scan, instead push 'columns[1]' which is the projected column into the scan.

        Attachments

        1. DRILL-1309.1.patch.txt
          76 kB
          Hanifi Gunes

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            • Assignee:
              DrillCommitter DrillCommitter
              Reporter:
              mehant Mehant Baid
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              • Created:
                Updated:
                Resolved: