Jesus Camacho Rodriguez created HIVE-13808:
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Summary: Use constant expressions to backtrack when we create
ReduceSink
Key: HIVE-13808
URL: https://issues.apache.org/jira/browse/HIVE-13808
Project: Hive
Issue Type: Sub-task
Components: Parser
Affects Versions: 2.1.0
Reporter: Jesus Camacho Rodriguez
Assignee: Jesus Camacho Rodriguez
Follow-up of HIVE-13068.
When we create a RS with constant expressions as keys/values, and immediately
after we create a SEL operator that backtracks the expressions from the RS.
Currently, we automatically create references for all the keys/values.
Before, we could rely on Hive ConstantPropagate to propagate the constants to
the SEL. However, after HIVE-13068, Hive ConstantPropagate does not get
exercised anymore. Thus, we can simply create constant expressions when we
create the SEL operator instead of a reference.
Ex. ql/src/test/results/clientpositive/vector_coalesce.q.out
{noformat}
EXPLAIN SELECT cdouble, cstring1, cint, cfloat, csmallint, coalesce(cdouble,
cstring1, cint, cfloat, csmallint) as c
FROM alltypesorc
WHERE (cdouble IS NULL)
ORDER BY cdouble, cstring1, cint, cfloat, csmallint, c
LIMIT 10
{noformat}
Plan:
{noformat}
EXPLAIN SELECT cdouble, cstring1, cint, cfloat, csmallint, coalesce(cdouble,
cstring1, cint, cfloat, csmallint) as c
FROM alltypesorc
WHERE (cdouble IS NULL)
ORDER BY cdouble, cstring1, cint, cfloat, csmallint, c
LIMIT 10
POSTHOOK: type: QUERY
STAGE DEPENDENCIES:
Stage-1 is a root stage
Stage-0 depends on stages: Stage-1
STAGE PLANS:
Stage: Stage-1
Map Reduce
Map Operator Tree:
TableScan
alias: alltypesorc
Statistics: Num rows: 12288 Data size: 2641964 Basic stats:
COMPLETE Column stats: NONE
Filter Operator
predicate: cdouble is null (type: boolean)
Statistics: Num rows: 6144 Data size: 1320982 Basic stats:
COMPLETE Column stats: NONE
Select Operator
expressions: cstring1 (type: string), cint (type: int), cfloat
(type: float), csmallint (type: smallint),
COALESCE(null,cstring1,cint,cfloat,csmallint) (type: string)
outputColumnNames: _col1, _col2, _col3, _col4, _col5
Statistics: Num rows: 6144 Data size: 1320982 Basic stats:
COMPLETE Column stats: NONE
Reduce Output Operator
key expressions: null (type: double), _col1 (type: string),
_col2 (type: int), _col3 (type: float), _col4 (type: smallint), _col5 (type:
string)
sort order: ++++++
Statistics: Num rows: 6144 Data size: 1320982 Basic stats:
COMPLETE Column stats: NONE
TopN Hash Memory Usage: 0.1
Execution mode: vectorized
Reduce Operator Tree:
Select Operator
expressions: KEY.reducesinkkey0 (type: double), KEY.reducesinkkey1
(type: string), KEY.reducesinkkey2 (type: int), KEY.reducesinkkey3 (type:
float), KEY.reducesinkkey4 (type: smallint), KEY.reducesinkkey5 (type: string)
outputColumnNames: _col0, _col1, _col2, _col3, _col4, _col5
Statistics: Num rows: 6144 Data size: 1320982 Basic stats: COMPLETE
Column stats: NONE
Limit
Number of rows: 10
Statistics: Num rows: 10 Data size: 2150 Basic stats: COMPLETE
Column stats: NONE
File Output Operator
compressed: false
Statistics: Num rows: 10 Data size: 2150 Basic stats: COMPLETE
Column stats: NONE
table:
input format: org.apache.hadoop.mapred.SequenceFileInputFormat
output format:
org.apache.hadoop.hive.ql.io.HiveSequenceFileOutputFormat
serde: org.apache.hadoop.hive.serde2.lazy.LazySimpleSerDe
Stage: Stage-0
Fetch Operator
limit: 10
Processor Tree:
ListSink
{noformat}
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