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https://issues.apache.org/jira/browse/HIVE-10716?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14560400#comment-14560400
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Gopal V commented on HIVE-10716:
--------------------------------
[~ashutoshc]: LGTM - +1 for the count(1) case, but it looks really odd that the
{{TableScan::filterExpr}} is not getting folded for this.
TableScan FilterExpr is populated before this folding happens, so it might just
be an optimization ordering issue?
{code}
hive> explain select count(1) from store_sales where (case ss_sold_date when
'x' then 1 else null end)=1;
STAGE PLANS:
Stage: Stage-1
Tez
Edges:
Reducer 2 <- Map 1 (SIMPLE_EDGE)
DagName: gopal_20150526214205_80c41d84-1694-47e9-ab24-144f8007b187:13
Vertices:
Map 1
Map Operator Tree:
TableScan
alias: store_sales
filterExpr: CASE (ss_sold_date) WHEN ('x') THEN (true) ELSE
(null) END (type: int)
Statistics: Num rows: 1 Data size: 0 Basic stats: PARTIAL
Column stats: COMPLETE
Filter Operator
predicate: (ss_sold_date = 'x') (type: boolean)
Statistics: Num rows: 1 Data size: 0 Basic stats: PARTIAL
Column stats: COMPLETE
Select Operator
Statistics: Num rows: 1 Data size: 0 Basic stats: PARTIAL
Column stats: COMPLETE
Group By Operator
aggregations: count(1)
mode: hash
outputColumnNames: _col0
Statistics: Num rows: 1 Data size: 93 Basic stats:
COMPLETE Column stats: COMPLETE
Reduce Output Operator
sort order:
Statistics: Num rows: 1 Data size: 93 Basic stats:
COMPLETE Column stats: COMPLETE
value expressions: _col0 (type: bigint)
Execution mode: vectorized
Reducer 2
Reduce Operator Tree:
Group By Operator
aggregations: count(VALUE._col0)
{code}
> Fold case/when udf for expression involving nulls in filter operator.
> ---------------------------------------------------------------------
>
> Key: HIVE-10716
> URL: https://issues.apache.org/jira/browse/HIVE-10716
> Project: Hive
> Issue Type: New Feature
> Components: Logical Optimizer
> Affects Versions: 1.3.0
> Reporter: Ashutosh Chauhan
> Assignee: Ashutosh Chauhan
> Attachments: HIVE-10716.patch
>
>
> From HIVE-10636 comments, more folding is possible.
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