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https://issues.apache.org/jira/browse/HIVE-21289?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17062605#comment-17062605
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David Mollitor commented on HIVE-21289:
---------------------------------------

[~kgyrtkirk] [~jcamachorodriguez] Are you able to take a peek at this?

> Expect EQ and LIKE to Generate the Identical Explain Plans
> ----------------------------------------------------------
>
>                 Key: HIVE-21289
>                 URL: https://issues.apache.org/jira/browse/HIVE-21289
>             Project: Hive
>          Issue Type: Improvement
>          Components: CBO, Logical Optimizer
>    Affects Versions: 2.3.4
>            Reporter: David Mollitor
>            Priority: Minor
>
> I generated some test data with the UUID function.
> {code:sql}
> explain select * from test_like where a like 
> 'abce6254-d437-426b-8873-2cbc153ddfbc';
> explain select * from test_like where a = 
> 'abce6254-d437-426b-8873-2cbc153ddfbc';
> {code}
> {code}
> Explain
> STAGE DEPENDENCIES:
>   Stage-1 is a root stage
>   Stage-0 depends on stages: Stage-1
> STAGE PLANS:
>   Stage: Stage-1
>     Map Reduce
>       Map Operator Tree:
>           TableScan
>             alias: test_like
>             filterExpr: (a like 'abce6254-d437-426b-8873-2cbc153ddfbc') 
> (type: boolean)
>             Statistics: Num rows: 262144 Data size: 9437184 Basic stats: 
> COMPLETE Column stats: NONE
>             Filter Operator
>               predicate: (a like 'abce6254-d437-426b-8873-2cbc153ddfbc') 
> (type: boolean)
>               Statistics: Num rows: 131072 Data size: 4718592 Basic stats: 
> COMPLETE Column stats: NONE
>               Select Operator
>                 expressions: a (type: string)
>                 outputColumnNames: _col0
>                 Statistics: Num rows: 131072 Data size: 4718592 Basic stats: 
> COMPLETE Column stats: NONE
>                 File Output Operator
>                   compressed: false
>                   Statistics: Num rows: 131072 Data size: 4718592 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
>   Stage: Stage-0
>     Fetch Operator
>       limit: -1
>       Processor Tree:
>         ListSink
> {code}
> {code}
> Explain
> STAGE DEPENDENCIES:
>   Stage-1 is a root stage
>   Stage-0 depends on stages: Stage-1
> STAGE PLANS:
>   Stage: Stage-1
>     Map Reduce
>       Map Operator Tree:
>           TableScan
>             alias: test_like
>             filterExpr: (a = 'abce6254-d437-426b-8873-2cbc153ddfbc') (type: 
> boolean)
>             Statistics: Num rows: 262144 Data size: 9437184 Basic stats: 
> COMPLETE Column stats: NONE
>             Filter Operator
>               predicate: (a = 'abce6254-d437-426b-8873-2cbc153ddfbc') (type: 
> boolean)
>               Statistics: Num rows: 131072 Data size: 4718592 Basic stats: 
> COMPLETE Column stats: NONE
>               Select Operator
>                 expressions: 'abce6254-d437-426b-8873-2cbc153ddfbc' (type: 
> string)
>                 outputColumnNames: _col0
>                 Statistics: Num rows: 131072 Data size: 4718592 Basic stats: 
> COMPLETE Column stats: NONE
>                 File Output Operator
>                   compressed: false
>                   Statistics: Num rows: 131072 Data size: 4718592 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
>   Stage: Stage-0
>     Fetch Operator
>       limit: -1
>       Processor Tree:
>         ListSink
> {code}
> They may be the same under the covers, but I would expect the EXPLAIN plan to 
> be exactly the same.



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