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Posted to dev@hive.apache.org by "Szehon Ho (JIRA)" <ji...@apache.org> on 2014/11/21 19:56:34 UTC

[jira] [Resolved] (HIVE-8701) Combine nested map joins into the parent map join if possible [Spark Branch]

     [ https://issues.apache.org/jira/browse/HIVE-8701?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]

Szehon Ho resolved HIVE-8701.
-----------------------------
    Resolution: Not a Problem

Resolving as investigation complete.  Created HIVE-8943 to track fixing of memory check.

> Combine nested map joins into the parent map join if possible [Spark Branch]
> ----------------------------------------------------------------------------
>
>                 Key: HIVE-8701
>                 URL: https://issues.apache.org/jira/browse/HIVE-8701
>             Project: Hive
>          Issue Type: Sub-task
>          Components: Spark
>            Reporter: Xuefu Zhang
>            Assignee: Szehon Ho
>
> With the work in HIVE-8616 enabled, the generated plan shows that the nested map join operator isn't merged to its parent when possible. This is demonstrated in auto_join2.q. The MR plan shown that this optimization is in place. We should do the same for Spark.
> {code}
> STAGE PLANS:
>   Stage: Stage-1
>     Spark
>       Edges:
>         Map 2 <- Map 3 (NONE, 0)
>         Map 3 <- Map 1 (NONE, 0)
>       DagName: xzhang_20141102074141_ac089634-bf01-4386-b1cf-3e7f2e99f6eb:3
>       Vertices:
>         Map 1 
>             Map Operator Tree:
>                 TableScan
>                   alias: src2
>                   Statistics: Num rows: 58 Data size: 5812 Basic stats: COMPLETE Column stats: NONE
>                   Filter Operator
>                     predicate: key is not null (type: boolean)
>                     Statistics: Num rows: 29 Data size: 2906 Basic stats: COMPLETE Column stats: NONE
>                     Reduce Output Operator
>                       key expressions: key (type: string)
>                       sort order: +
>                       Map-reduce partition columns: key (type: string)
>                       Statistics: Num rows: 29 Data size: 2906 Basic stats: COMPLETE Column stats: NONE
>         Map 2 
>             Map Operator Tree:
>                 TableScan
>                   alias: src3
>                   Statistics: Num rows: 29 Data size: 5812 Basic stats: COMPLETE Column stats: NONE
>                   Filter Operator
>                     predicate: UDFToDouble(key) is not null (type: boolean)
>                     Statistics: Num rows: 15 Data size: 3006 Basic stats: COMPLETE Column stats: NONE
>                     Map Join Operator
>                       condition map:
>                            Inner Join 0 to 1
>                       condition expressions:
>                         0 {_col0}
>                         1 {value}
>                       keys:
>                         0 (_col0 + _col5) (type: double)
>                         1 UDFToDouble(key) (type: double)
>                       outputColumnNames: _col0, _col11
>                       input vertices:
>                         0 Map 3
>                       Statistics: Num rows: 17 Data size: 1813 Basic stats: COMPLETE Column stats: NONE
>                       Select Operator
>                         expressions: _col0 (type: string), _col11 (type: string)
>                         outputColumnNames: _col0, _col1
>                         Statistics: Num rows: 17 Data size: 1813 Basic stats: COMPLETE Column stats: NONE
>                         File Output Operator
>                           compressed: false
>                           Statistics: Num rows: 17 Data size: 1813 Basic stats: COMPLETE Column stats: NONE
>                           table:
>                               input format: org.apache.hadoop.mapred.TextInputFormat
>                               output format: org.apache.hadoop.hive.ql.io.HiveIgnoreKeyTextOutputFormat
>                               serde: org.apache.hadoop.hive.serde2.lazy.LazySimpleSerDe
>         Map 3 
>             Map Operator Tree:
>                 TableScan
>                   alias: src1
>                   Statistics: Num rows: 58 Data size: 5812 Basic stats: COMPLETE Column stats: NONE
>                   Filter Operator
>                     predicate: key is not null (type: boolean)
>                     Statistics: Num rows: 29 Data size: 2906 Basic stats: COMPLETE Column stats: NONE
>                     Map Join Operator
>                       condition map:
>                            Inner Join 0 to 1
>                       condition expressions:
>                         0 {key}
>                         1 {key}
>                       keys:
>                         0 key (type: string)
>                         1 key (type: string)
>                       outputColumnNames: _col0, _col5
>                       input vertices:
>                         1 Map 1
>                       Statistics: Num rows: 31 Data size: 3196 Basic stats: COMPLETE Column stats: NONE
>                       Filter Operator
>                         predicate: (_col0 + _col5) is not null (type: boolean)
>                         Statistics: Num rows: 16 Data size: 1649 Basic stats: COMPLETE Column stats: NONE
>                         Reduce Output Operator
>                           key expressions: (_col0 + _col5) (type: double)
>                           sort order: +
>                           Map-reduce partition columns: (_col0 + _col5) (type: double)
>                           Statistics: Num rows: 16 Data size: 1649 Basic stats: COMPLETE Column stats: NONE
>                           value expressions: _col0 (type: string)
> {code}



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