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https://issues.apache.org/jira/browse/HIVE-14302?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
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Mustafa Iman updated HIVE-14302:
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Attachment: HIVE-14302.5.patch
Status: Patch Available (was: In Progress)
Forgot to add llap/mapjoin_decimal_vectorized.q.out before. Now adding
> Tez: Optimized Hashtable can support DECIMAL keys of same precision
> -------------------------------------------------------------------
>
> Key: HIVE-14302
> URL: https://issues.apache.org/jira/browse/HIVE-14302
> Project: Hive
> Issue Type: Improvement
> Components: Tez
> Affects Versions: 2.2.0
> Reporter: Gopal Vijayaraghavan
> Assignee: Mustafa Iman
> Priority: Major
> Labels: pull-request-available
> Attachments: HIVE-14302.2.patch, HIVE-14302.3.patch,
> HIVE-14302.4.patch, HIVE-14302.5.patch, HIVE-14302.patch
>
> Time Spent: 40m
> Remaining Estimate: 0h
>
> Decimal support in the optimized hashtable was decided on the basis of the
> fact that Decimal(10,1) == Decimal(10, 2) when both contain "1.0" and "1.00".
> However, the joins now don't have any issues with decimal precision because
> they cast to common.
> {code}
> create temporary table x (a decimal(10,2), b decimal(10,1)) stored as orc;
> insert into x values (1.0, 1.0);
> > explain logical select count(1) from x, x x1 where x.a = x1.b;
> OK
> LOGICAL PLAN:
> $hdt$_0:$hdt$_0:x
> TableScan (TS_0)
> alias: x
> filterExpr: (a is not null and true) (type: boolean)
> Filter Operator (FIL_18)
> predicate: (a is not null and true) (type: boolean)
> Select Operator (SEL_2)
> expressions: a (type: decimal(10,2))
> outputColumnNames: _col0
> Reduce Output Operator (RS_6)
> key expressions: _col0 (type: decimal(11,2))
> sort order: +
> Map-reduce partition columns: _col0 (type: decimal(11,2))
> Join Operator (JOIN_8)
> condition map:
> Inner Join 0 to 1
> keys:
> 0 _col0 (type: decimal(11,2))
> 1 _col0 (type: decimal(11,2))
> Group By Operator (GBY_11)
> aggregations: count(1)
> mode: hash
> outputColumnNames: _col0
> {code}
> See cast up to Decimal(11, 2) in the plan, which normalizes both sides of the
> join to be able to compare HiveDecimal as-is.
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