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Posted to dev@drill.apache.org by "Deneche A. Hakim (JIRA)" <ji...@apache.org> on 2015/06/26 19:27:04 UTC

[jira] [Created] (DRILL-3397) over(partition by A order by A) should be optimized to over(partition by A)

Deneche A. Hakim created DRILL-3397:
---------------------------------------

             Summary: over(partition by A order by A) should be optimized to over(partition by A)
                 Key: DRILL-3397
                 URL: https://issues.apache.org/jira/browse/DRILL-3397
             Project: Apache Drill
          Issue Type: Improvement
          Components: Query Planning & Optimization
            Reporter: Deneche A. Hakim
            Assignee: Jinfeng Ni
             Fix For: 1.2.0


although the following queries return the same results, they have different plans: 
{noformat}
EXPLAIN PLAN FOR SELECT SUM(salary) OVER(PARTITION BY position_id) FROM cp.`employee.json`;

00-00    Screen
00-01      Project(EXPR$0=[CASE(>($2, 0), $3, null)])
00-02        Window(window#0=[window(partition {1} order by [] range between UNBOUNDED PRECEDING and UNBOUNDED FOLLOWING aggs [COUNT($0), $SUM0($0)])])
00-03          SelectionVectorRemover
00-04            Sort(sort0=[$1], dir0=[ASC])
00-05              Project(salary=[$1], position_id=[$0])
00-06                Scan(groupscan=[EasyGroupScan [selectionRoot=/employee.json, numFiles=1, columns=[`salary`, `position_id`], files=[classpath:/employee.json]]])
{noformat}

{noformat}
EXPLAIN PLAN FOR SELECT SUM(salary) OVER(PARTITION BY position_id ORDER BY position_id) FROM cp.`employee.json`;

00-00    Screen
00-01      Project(EXPR$0=[CASE(>($2, 0), $3, null)])
00-02        Window(window#0=[window(partition {1} order by [1] range between UNBOUNDED PRECEDING and CURRENT ROW aggs [COUNT($0), $SUM0($0)])])
00-03          SelectionVectorRemover
00-04            Sort(sort0=[$1], sort1=[$1], dir0=[ASC], dir1=[ASC])
00-05              Project(salary=[$1], position_id=[$0])
00-06                Scan(groupscan=[EasyGroupScan [selectionRoot=/employee.json, numFiles=1, columns=[`salary`, `position_id`], files=[classpath:/employee.json]]])
{noformat}

Drill should detect such cases and remove the order-by from the plan.



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