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https://issues.apache.org/jira/browse/SPARK-21520?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
 ]

caoxuewen updated SPARK-21520:
------------------------------
    Summary: Improvement a special case for non-deterministic projects and 
filters in optimizer  (was: Hivetable scan for all the columns the SQL 
statement contains the 'rand')

> Improvement a special case for non-deterministic projects and filters in 
> optimizer
> ----------------------------------------------------------------------------------
>
>                 Key: SPARK-21520
>                 URL: https://issues.apache.org/jira/browse/SPARK-21520
>             Project: Spark
>          Issue Type: Improvement
>          Components: SQL
>    Affects Versions: 2.3.0
>            Reporter: caoxuewen
>
> Currently, when the rand function is present in the SQL statement, hivetable 
> searches all columns in the table.
> e.g:
> select k,k,sum(id) from (select d004 as id, floor(rand() * 10000) as k, 
> ceil(c010) as cceila from XXX_table) a
> group by k,k;
> generate WholeStageCodegen subtrees:
> == Subtree 1 / 2 ==
> *HashAggregate(keys=[k#403L], functions=[partial_sum(cast(id#402 as 
> bigint))], output=[k#403L, sum#800L])
> +- Project [d004#607 AS id#402, FLOOR((rand(8828525941469309371) * 10000.0)) 
> AS k#403L]
>    +- HiveTableScan [c030#606L, d004#607, d005#608, d025#609, c002#610, 
> d023#611, d024#612, c005#613L, c008#614, c009#615, c010#616, d021#617, 
> d022#618, c017#619, c018#620, c019#621, c020#622, c021#623, c022#624, 
> c023#625, c024#626, c025#627, c026#628, c027#629, ... 169 more fields], 
> MetastoreRelation XXX_database, XXX_table
> == Subtree 2 / 2 ==
> *HashAggregate(keys=[k#403L], functions=[sum(cast(id#402 as bigint))], 
> output=[k#403L, k#403L, sum(id)#797L])
> +- Exchange hashpartitioning(k#403L, 200)
>    +- *HashAggregate(keys=[k#403L], functions=[partial_sum(cast(id#402 as 
> bigint))], output=[k#403L, sum#800L])
>       +- Project [d004#607 AS id#402, FLOOR((rand(8828525941469309371) * 
> 10000.0)) AS k#403L]
>          +- HiveTableScan [c030#606L, d004#607, d005#608, d025#609, c002#610, 
> d023#611, d024#612, c005#613L, c008#614, c009#615, c010#616, d021#617, 
> d022#618, c017#619, c018#620, c019#621, c020#622, c021#623, c022#624, 
> c023#625, c024#626, c025#627, c026#628, c027#629, ... 169 more fields], 
> MetastoreRelation XXX_database, XXX_table
>                
> All columns will be searched in HiveTableScans , Consequently, All column 
> data is read to a ORC table.
> e.g:
> INFO ReaderImpl: Reading ORC rows from 
> hdfs://opena:8020/.../XXX_table/.../p_date=2017-05-25/p_hour=10/part-00009 
> with {include: [true, true, true, true, true, true, true, true, true, true, 
> true, true, true, true, true, true, true, true, true, true, true, true, true, 
> true, true, true, true, true, true, true, true, true, true, true, true, true, 
> true, true, true, true, true, true, true, true, true, true, true, true, true, 
> true, true, true, true, true, true, true, true, true, true, true, true, true, 
> true, true, true, true, true, true, true, true, true, true, true, true, true, 
> true, true, true, true, true, true, true, true, true, true, true, true, true, 
> true, true, true, true, true, true, true, true, true, true, true, true, true, 
> true, true, true, true, true, true, true, true, true, true, true, true, true, 
> true, true, true, true, true, true, true], offset: 0, length: 
> 9223372036854775807}
> so, The execution of the SQL statement will become very slow.



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