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Posted to issues@drill.apache.org by "Serhii Harnyk (JIRA)" <ji...@apache.org> on 2016/11/01 05:53:58 UTC

[jira] [Commented] (DRILL-4944) incorrect results - case expression

    [ https://issues.apache.org/jira/browse/DRILL-4944?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15624468#comment-15624468 ] 

Serhii Harnyk commented on DRILL-4944:
--------------------------------------

[~khfaraaz] Drill uses Calcite more like a query parser/planner/optimizator. Drill has its own types and type handling logic. 

> incorrect results - case expression
> -----------------------------------
>
>                 Key: DRILL-4944
>                 URL: https://issues.apache.org/jira/browse/DRILL-4944
>             Project: Apache Drill
>          Issue Type: Bug
>          Components: Execution - Flow
>    Affects Versions: 1.9.0
>            Reporter: Khurram Faraaz
>            Assignee: Serhii Harnyk
>            Priority: Critical
>             Fix For: 1.9.0
>
>
> Drill 1.9.0 (git commit id: 4edabe7a) returns null, which is wrong.
>  {noformat}
>  0: jdbc:drill:schema=dfs.tmp> SELECT res2, case res2 WHEN 0.1 THEN 0.9999 ELSE null END
> . . . . . . . . . . . . . . > FROM
> . . . . . . . . . . . . . . > (
> . . . . . . . . . . . . . . >     SELECT
> . . . . . . . . . . . . . . >     (CASE WHEN (false) THEN null ELSE CAST(0.1 as float) end) res2
> . . . . . . . . . . . . . . >     FROM (values(1)) foo
> . . . . . . . . . . . . . . > ) foobar ;
> +-------+---------+
> | res2  | EXPR$1  |
> +-------+---------+
> | 0.1   | null    |
> +-------+---------+
> 1 row selected (0.106 seconds)
>  {noformat}
>  
>  Postgres returns correct results
>   {noformat}
>  postgres=# SELECT res2, case res2 WHEN 0.1 THEN 0.9999 ELSE null END
> postgres-# FROM
> postgres-# (
> postgres(#     SELECT
> postgres(#     (CASE WHEN (false) THEN null ELSE CAST(0.1 as float) end) res2
> postgres(#     FROM (values(1)) foo
> postgres(# ) foobar ;
>  res2 |  case
> ------+--------
>   0.1 | 0.9999
> (1 row)
>  {noformat}
>  
>  Calcite also returns correct results
>   {noformat}
>  0: jdbc:calcite:model=target/test-classes/mod> SELECT res2, case res2 WHEN 0.1 THEN 0.9999 ELSE null END
> . . . . . . . . . . . . . . . . . . . . . . .> FROM
> . . . . . . . . . . . . . . . . . . . . . . .> (
> . . . . . . . . . . . . . . . . . . . . . . .>       SELECT
> . . . . . . . . . . . . . . . . . . . . . . .>          (CASE WHEN (false) THEN null ELSE CAST(0.1 as float) end) res2
> . . . . . . . . . . . . . . . . . . . . . . .>      FROM (values(1)) foo
> . . . . . . . . . . . . . . . . . . . . . . .> ) foobar ;
> +-----------------+--------+
> |      RES2       | EXPR$1 |
> +-----------------+--------+
> | 0.1             | 0.9999 |
> +-----------------+--------+
> 1 row selected (1.277 seconds)
>  {noformat}
>  
>  Details of explain plan from Drill 1.9.0
>   {noformat}
>  0: jdbc:drill:schema=dfs.tmp> explain plan for SELECT res2, case res2 WHEN 0.1 THEN 0.9999 ELSE null END
> . . . . . . . . . . . . . . > FROM
> . . . . . . . . . . . . . . > (
> . . . . . . . . . . . . . . >       SELECT
> . . . . . . . . . . . . . . >          (CASE WHEN (false) THEN null ELSE CAST(0.1 as float) end) res2
> . . . . . . . . . . . . . . >      FROM (values(1)) foo
> . . . . . . . . . . . . . . > ) foobar ;
> +------+------+
> | text | json |
> +------+------+
> | 00-00    Screen
> 00-01      Project(res2=[$0], EXPR$1=[$1])
> 00-02        Project(res2=[CASE(false, null, 0.1)], EXPR$1=[CASE(=(CASE(false, null, 0.1), 0.1), 0.9999, null)])
> 00-03          Values
>  | {
>   "head" : {
>     "version" : 1,
>     "generator" : {
>       "type" : "ExplainHandler",
>       "info" : ""
>     },
>     "type" : "APACHE_DRILL_PHYSICAL",
>     "options" : [ ],
>     "queue" : 0,
>     "resultMode" : "EXEC"
>   },
>   "graph" : [ {
>     "pop" : "Values",
>     "@id" : 3,
>     "content" : [ {
>       "EXPR$0" : {
>         "$numberLong" : 1
>       }
>     } ],
>     "initialAllocation" : 1000000,
>     "maxAllocation" : 10000000000,
>     "cost" : 1.0
>   }, {
>     "pop" : "project",
>     "@id" : 2,
>     "exprs" : [ {
>       "ref" : "`res2`",
>       "expr" : " ( if (false ) then (NULL )  else (0.1 )  end  ) "
>     }, {
>       "ref" : "`EXPR$1`",
>       "expr" : " ( if (equal( ( if (false ) then (NULL )  else (0.1 )  end  ) , 0.1)  ) then (0.9999 )  else (NULL )  end  ) "
>     } ],
>     "child" : 3,
>     "initialAllocation" : 1000000,
>     "maxAllocation" : 10000000000,
>     "cost" : 1.0
>   }, {
>     "pop" : "project",
>     "@id" : 1,
>     "exprs" : [ {
>       "ref" : "`res2`",
>       "expr" : "`res2`"
>     }, {
>       "ref" : "`EXPR$1`",
>       "expr" : "`EXPR$1`"
>     } ],
>     "child" : 2,
>     "initialAllocation" : 1000000,
>     "maxAllocation" : 10000000000,
>     "cost" : 1.0
>   }, {
>     "pop" : "screen",
>     "@id" : 0,
>     "child" : 1,
>     "initialAllocation" : 1000000,
>     "maxAllocation" : 10000000000,
>     "cost" : 1.0
>   } ]
> } |
>  {noformat}



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