[DRILL-1690] Issue with using HBase plugin to access row_key only

• Type: Bug
• Status: Resolved
• Priority: Critical
• Resolution: Fixed
• Fix Version/s: 0.8.0
• Component/s: Storage - HBase
• Assignee: Aditya Kishore
• Reporter: Chun Chang
• Created: 12/Nov/14 00:30
• Updated: 25/Feb/15 21:46
• Resolved: 25/Feb/15 21:46

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.