Details
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Bug
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Status: Closed
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Major
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Resolution: Fixed
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None
Description
Currently for a query involving join on multiple columns creates separate semi join edges for each key which in turn create a bloom filter for each of them, like below,
EXPLAIN select count
from srcpart_date_n7 join srcpart_small_n3 on (srcpart_date_n7.key = srcpart_small_n3.key1 and srcpart_date_n7.value = srcpart_small_n3.value1)
Map 1 <- Reducer 5 (BROADCAST_EDGE)
Reducer 2 <- Map 1 (SIMPLE_EDGE), Map 4 (SIMPLE_EDGE)
Reducer 3 <- Reducer 2 (CUSTOM_SIMPLE_EDGE)
Reducer 5 <- Map 4 (CUSTOM_SIMPLE_EDGE)
#### A masked pattern was here ####
Vertices:
Map 1
Map Operator Tree:
TableScan
alias: srcpart_date_n7
filterExpr: (key is not null and value is not null and (key BETWEEN DynamicValue(RS_7_srcpart_small_n3_key1_min) AND DynamicValue(RS_7_srcpart_small_n3_key1_max) and in_bloom_filter(key, DynamicValue(RS_7_srcpart_small_n3_key1_bloom_filter)))) (type: boolean)
Statistics: Num rows: 2000 Data size: 356000 Basic stats: COMPLETE Column stats: COMPLETE
Filter Operator
predicate: ((key BETWEEN DynamicValue(RS_7_srcpart_small_n3_key1_min) AND DynamicValue(RS_7_srcpart_small_n3_key1_max) and in_bloom_filter(key, DynamicValue(RS_7_srcpart_small_n3_key1_bloom_filter))) and key is not null and value is not null) (type: boolean)
Statistics: Num rows: 2000 Data size: 356000 Basic stats: COMPLETE Column stats: COMPLETE
Select Operator
expressions: key (type: string), value (type: string)
outputColumnNames: _col0, _col1
Statistics: Num rows: 2000 Data size: 356000 Basic stats: COMPLETE Column stats: COMPLETE
Reduce Output Operator
key expressions: _col0 (type: string), _col1 (type: string)
sort order: ++
Map-reduce partition columns: _col0 (type: string), _col1 (type: string)
Statistics: Num rows: 2000 Data size: 356000 Basic stats: COMPLETE Column stats: COMPLETE
Execution mode: vectorized, llap
LLAP IO: all inputs
Map 4
Map Operator Tree:
TableScan
alias: srcpart_small_n3
filterExpr: (key1 is not null and value1 is not null) (type: boolean)
Statistics: Num rows: 20 Data size: 3560 Basic stats: PARTIAL Column stats: PARTIAL
Filter Operator
predicate: (key1 is not null and value1 is not null) (type: boolean)
Statistics: Num rows: 20 Data size: 3560 Basic stats: PARTIAL Column stats: PARTIAL
Select Operator
expressions: key1 (type: string), value1 (type: string)
outputColumnNames: _col0, _col1
Statistics: Num rows: 20 Data size: 3560 Basic stats: PARTIAL Column stats: PARTIAL
Reduce Output Operator
key expressions: _col0 (type: string), _col1 (type: string)
sort order: ++
Map-reduce partition columns: _col0 (type: string), _col1 (type: string)
Statistics: Num rows: 20 Data size: 3560 Basic stats: PARTIAL Column stats: PARTIAL
Select Operator
expressions: _col0 (type: string)
outputColumnNames: _col0
Statistics: Num rows: 20 Data size: 3560 Basic stats: PARTIAL Column stats: PARTIAL
Group By Operator
aggregations: min(_col0), max(_col0), bloom_filter(_col0, expectedEntries=20)
mode: hash
outputColumnNames: _col0, _col1, _col2
Statistics: Num rows: 1 Data size: 730 Basic stats: PARTIAL Column stats: PARTIAL
Reduce Output Operator
sort order:
Statistics: Num rows: 1 Data size: 730 Basic stats: PARTIAL Column stats: PARTIAL
value expressions: _col0 (type: string), _col1 (type: string), _col2 (type: binary)
Execution mode: vectorized, llap
LLAP IO: all inputs
Reducer 2
Execution mode: llap
Reduce Operator Tree:
Merge Join Operator
condition map:
Inner Join 0 to 1
keys:
0 _col0 (type: string), _col1 (type: string)
1 _col0 (type: string), _col1 (type: string)
Statistics: Num rows: 2200 Data size: 391600 Basic stats: PARTIAL Column stats: NONE
Group By Operator
aggregations: count()
mode: hash
outputColumnNames: _col0
Statistics: Num rows: 1 Data size: 8 Basic stats: PARTIAL Column stats: NONE
Reduce Output Operator
sort order:
Statistics: Num rows: 1 Data size: 8 Basic stats: PARTIAL Column stats: NONE
value expressions: _col0 (type: bigint)
Reducer 3
Execution mode: vectorized, llap
Reduce Operator Tree:
Group By Operator
aggregations: count(VALUE._col0)
mode: mergepartial
outputColumnNames: _col0
Statistics: Num rows: 1 Data size: 8 Basic stats: PARTIAL Column stats: NONE
File Output Operator
compressed: false
Statistics: Num rows: 1 Data size: 8 Basic stats: PARTIAL 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
Reducer 5
Execution mode: vectorized, llap
Reduce Operator Tree:
Group By Operator
aggregations: min(VALUE._col0), max(VALUE._col1), bloom_filter(VALUE._col2, expectedEntries=20)
mode: final
outputColumnNames: _col0, _col1, _col2
Statistics: Num rows: 1 Data size: 730 Basic stats: PARTIAL Column stats: PARTIAL
Reduce Output Operator
sort order:
Statistics: Num rows: 1 Data size: 730 Basic stats: PARTIAL Column stats: PARTIAL
value expressions: _col0 (type: string), _col1 (type: string), _col2 (type: binary)
Instead it should create one branch for a join with one bloom filter.
The implementation for bloom filter requires getting a hash out of all the key columns and converting it to a long and feeding it to bloom filter as input. This requires a new UDF which does this. It will be called at both bloom filter generation and lookup phases.
The min and max will stay independent as they are today for each columns.
A vectorized implementation of such UDF is also required.
Attachments
Issue Links
- contains
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HIVE-23940 Add TPCH tables (scale factor 0.001) as qt datasets
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