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https://issues.apache.org/jira/browse/HIVE-5501?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13790624#comment-13790624
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Ashutosh Chauhan commented on HIVE-5501:
----------------------------------------
{code}
hive> create table t3 (a string, b int) partitioned by (p1 string);
hive> explain select count(*) from t3 where p1='3';
OK
ABSTRACT SYNTAX TREE:
(TOK_QUERY (TOK_FROM (TOK_TABREF (TOK_TABNAME t3))) (TOK_INSERT
(TOK_DESTINATION (TOK_DIR TOK_TMP_FILE)) (TOK_SELECT (TOK_SELEXPR
(TOK_FUNCTIONSTAR count))) (TOK_WHERE (= (TOK_TABLE_OR_COL p1) '3'))))
STAGE DEPENDENCIES:
Stage-1 is a root stage
Stage-0 is a root stage
STAGE PLANS:
Stage: Stage-1
Map Reduce
Alias -> Map Operator Tree:
t3
TableScan
alias: t3
>> Filter Operator
>> predicate:
>> expr: (p1 = '3')
>> type: boolean
Select Operator
Group By Operator
aggregations:
expr: count()
bucketGroup: false
mode: hash
outputColumnNames: _col0
Reduce Output Operator
sort order:
tag: -1
value expressions:
expr: _col0
type: bigint
Reduce Operator Tree:
Group By Operator
aggregations:
expr: count(VALUE._col0)
bucketGroup: false
mode: mergepartial
outputColumnNames: _col0
Select Operator
expressions:
expr: _col0
type: bigint
outputColumnNames: _col0
File Output Operator
compressed: false
GlobalTableId: 0
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
{code}
Filter marked by >> is not useful at execution time and should have been
eliminated by optimizer since partitioning pruning will already take care of it.
> Filter on partitioning column shouldn't be present at execution time
> --------------------------------------------------------------------
>
> Key: HIVE-5501
> URL: https://issues.apache.org/jira/browse/HIVE-5501
> Project: Hive
> Issue Type: Improvement
> Components: Query Processor
> Reporter: Ashutosh Chauhan
>
> Since such filters are already processed via partitioning pruning, having it
> present in operator pipeline is unnecessary overhead.
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