[
https://issues.apache.org/jira/browse/DRILL-861?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14012986#comment-14012986
]
Chun Chang commented on DRILL-861:
----------------------------------
here is the plan:
0: jdbc:drill:schema=dfs> explain plan for select sum(cast(c_decimal38 as
decimal(38,14))) from data where c_row <= 14;
+------------+------------+
| text | json |
+------------+------------+
| 00-00 Screen
00-01 StreamAgg(group=[{}], EXPR$0=[SUM($0)])
00-02 UnionExchange
01-01 StreamAgg(group=[{}], EXPR$0=[SUM($0)])
01-02 Project($f0=[CAST($2):DECIMAL(38, 14)])
01-03 SelectionVectorRemover
01-04 Filter(condition=[<=($1, 14)])
01-05 Scan(groupscan=[ParquetGroupScan
[entries=[ReadEntryWithPath [path=maprfs:/user/root/mondrian/data]],
selectionRoot=/user/root/mondrian/data, columns=[SchemaPath [`c_row`],
SchemaPath [`c_decimal38`]]]])
| {
"head" : {
"version" : 1,
"generator" : {
"type" : "ExplainHandler",
"info" : ""
},
"type" : "APACHE_DRILL_PHYSICAL",
"options" : [ ],
"resultMode" : "EXEC"
},
"graph" : [ {
"pop" : "parquet-scan",
"@id" : 65541,
"entries" : [ {
"path" : "maprfs:/user/root/mondrian/data"
} ],
"storage" : {
"type" : "file",
"connection" : "maprfs:///",
"workspaces" : {
"default" : {
"location" : "/user/root/mondrian/",
"writable" : false,
"storageformat" : null
},
"home" : {
"location" : "/",
"writable" : false,
"storageformat" : null
},
"root" : {
"location" : "/",
"writable" : false,
"storageformat" : null
},
"tmp" : {
"location" : "/tmp",
"writable" : true,
"storageformat" : "csv"
}
},
"formats" : {
"psv" : {
"type" : "text",
"extensions" : [ "tbl" ],
"delimiter" : "|"
},
"csv" : {
"type" : "text",
"extensions" : [ "csv" ],
"delimiter" : ","
},
"tsv" : {
"type" : "text",
"extensions" : [ "tsv" ],
"delimiter" : "\t"
},
"parquet" : {
"type" : "parquet"
},
"json" : {
"type" : "json"
}
}
},
"format" : {
"type" : "parquet"
},
"columns" : [ "`c_row`", "`c_decimal38`" ],
"selectionRoot" : "/user/root/mondrian/data"
}, {
"pop" : "filter",
"@id" : 65540,
"child" : 65541,
"expr" : "less_than_or_equal_to(`c_row`, 14) ",
"initialAllocation" : 1000000,
"maxAllocation" : 10000000000
}, {
"pop" : "selection-vector-remover",
"@id" : 65539,
"child" : 65540,
"initialAllocation" : 1000000,
"maxAllocation" : 10000000000
}, {
"pop" : "project",
"@id" : 65538,
"exprs" : [ {
"ref" : "`$f0`",
"expr" : "cast( (`c_decimal38` ) as DECIMAL38SPARSE(38, 14) )"
} ],
"child" : 65539,
"initialAllocation" : 1000000,
"maxAllocation" : 10000000000
}, {
"pop" : "streaming-aggregate",
"@id" : 65537,
"child" : 65538,
"keys" : [ ],
"exprs" : [ {
"ref" : "`EXPR$0`",
"expr" : "sum(`$f0`) "
} ],
"initialAllocation" : 1000000,
"maxAllocation" : 10000000000
}, {
"pop" : "union-exchange",
"@id" : 2,
"child" : 65537,
"initialAllocation" : 1000000,
"maxAllocation" : 10000000000
}, {
"pop" : "streaming-aggregate",
"@id" : 1,
"child" : 2,
"keys" : [ ],
"exprs" : [ {
"ref" : "`EXPR$0`",
"expr" : "sum(`EXPR$0`) "
} ],
"initialAllocation" : 1000000,
"maxAllocation" : 10000000000
}, {
"pop" : "screen",
"@id" : 0,
"child" : 1,
"initialAllocation" : 1000000,
"maxAllocation" : 10000000000
} ]
} |
+------------+------------+
1 row selected (0.228 seconds)
> sum(decimal38) gives wrong result, even without overflowing
> -----------------------------------------------------------
>
> Key: DRILL-861
> URL: https://issues.apache.org/jira/browse/DRILL-861
> Project: Apache Drill
> Issue Type: Bug
> Components: Functions - Drill
> Reporter: Chun Chang
> Assignee: Mehant Baid
>
> #Wed May 28 17:19:59 PDT 2014
> git.commit.id.abbrev=c8a08c3
> sum over decimal38 type of data gives wrong result. this is without encounter
> overflowing.
> I have the following data in a decimal38 column:
> 0: jdbc:drill:schema=dfs> select cast(c_decimal38 as decimal(38,14)) from
> data where c_row <= 14;
> +------------+
> | EXPR$0 |
> +------------+
> | 0E-14 |
> | 1.00000000000000 |
> | 123456789.00000000000000 |
> | 999999999.00000000000000 |
> | -999999999.00000000000000 |
> | 1.000000E-8 |
> | -1.000000E-8 |
> | 12345.67890000000000 |
> | 123456789.12345678900000 |
> | 999999999999999999.00000000000000 |
> | -999999999999999999.00000000000000 |
> | 0E-14 |
> | 0E-14 |
> | 12345678901234.12345678901234 |
> +------------+
> 14 rows selected (0.288 seconds)
> The sum of the columns gives the following wrong number:
> 0: jdbc:drill:schema=dfs> select sum(cast(c_decimal38 as decimal(38,14)))
> from data where c_row <= 14;
> +------------+
> | EXPR$0 |
> +------------+
> | 1.2345925827186123E13 |
> The correct number should be (from postgres, I also hand calculated):
> foodmart=# select sum(cast(c_decimal38 as decimal(38,14))) from data where
> c_row <= 14;
> sum
> -------------------------------
> 12345925827158.92581357801234
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