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  1. Apache Drill
  2. DRILL-1690

Issue with using HBase plugin to access row_key only

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    Details

    • Type: Bug
    • Status: Resolved
    • Priority: Critical
    • Resolution: Fixed
    • Affects Version/s: None
    • Fix Version/s: 0.8.0
    • Component/s: Storage - HBase
    • Labels:
      None

      Description

      #Thu Nov 06 11:38:17 PST 2014
      git.commit.id.abbrev=eeb7160

      Configure an HBase plugin to access MapRDB table. When, select the row key only, we return two columns:

      0: jdbc:drill:schema=M7> select row_key, fivecf from m7student limit 2;
      ----------------------+

      row_key fivecf

      ----------------------+

      [B@31966bd8 {"create_date":"MjAxNC0wNS0yNyAwMDoyNjowNw=="}
      [B@a824b57 {"create_date":"MjAxNC0wMy0yNCAyMTo1NzozMw=="}

      ----------------------+
      2 rows selected (0.128 seconds)
      0: jdbc:drill:schema=M7> select row_key from m7student limit 2;
      ----------------------+

      row_key fivecf

      ----------------------+

      [B@2560bab1 {"create_date":"MjAxNC0wNS0yNyAwMDoyNjowNw=="}
      [B@7180cda2 {"create_date":"MjAxNC0wMy0yNCAyMTo1NzozMw=="}

      ----------------------+
      2 rows selected (0.107 seconds)

      Here is the plan:

      0: jdbc:drill:schema=M7> explain plan for select row_key from m7student limit 2;
      ----------------------+

      text json

      ----------------------+

      00-00 Screen
      00-01 SelectionVectorRemover
      00-02 Limit(fetch=[2])
      00-03 Scan(groupscan=[HBaseGroupScan [HBaseScanSpec=HBaseScanSpec [tableName=m7student, startRow=null, stopRow=null, filter=null], columns=[SchemaPath [`row_key`]]]])
      {
      "head" :
      Unknown macro: { "version" }

      ,
      "graph" : [ {
      "pop" : "hbase-scan",
      "@id" : 3,
      "hbaseScanSpec" :

      { "tableName" : "m7student", "startRow" : "", "stopRow" : "", "serializedFilter" : null }

      ,
      "storage" :

      Unknown macro: { "type" }

      ,
      "columns" : [ "`row_key`" ],
      "cost" : 1048576.0
      },

      { "pop" : "limit", "@id" : 2, "child" : 3, "first" : 0, "last" : 2, "initialAllocation" : 1000000, "maxAllocation" : 10000000000, "cost" : 1048576.0 }

      ,

      { "pop" : "selection-vector-remover", "@id" : 1, "child" : 2, "initialAllocation" : 1000000, "maxAllocation" : 10000000000, "cost" : 1048576.0 }

      ,

      { "pop" : "screen", "@id" : 0, "child" : 1, "initialAllocation" : 1000000, "maxAllocation" : 10000000000, "cost" : 1048576.0 }

      ]
      }

      ----------------------+

      Drill should strip out the second column.

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            • Assignee:
              adityakishore Aditya Kishore
              Reporter:
              cchang@maprtech.com Chun Chang
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              Dates

              • Created:
                Updated:
                Resolved: