apache / apache/carbondata

FusionInsightHD 6518 spark2.3.2 carbon-2.0.0 skewedJoin adaptive execution no use.

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Dominant language
Scala
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Description

spark.sql.adaptive.enabled=true
spark.sql.adaptive.skewedJoin.enabled=true
spark.sql.adaptive.skewedPartitionMaxSplits=5
spark.sql.adaptive.skewedPartitionRowCountThreshold=10000000
spark.sql.adaptive.skewedPartitionSizeThreshold=67108864
spark.sql.adaptive.skewedPartitionFactor : 5

--- In Spark2x JDBC no use for it.

t1 left join t2 on t1.id = t2.id column id has one key, for example 0000-00-00 ,has 100,000 records t2 has same key in column id also has 100,000 records ,this will generate 100000*100000 = 10B records!! for only one reducer.

carbon solution no use for it,please check it. -- call hw.

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Research direction

Start by reproducing the reported left join with the listed adaptive-execution settings on FusionInsightHD 6518, Spark 2.3.2, and carbon-2.0.0, comparing Spark2x JDBC behavior with the Carbon solution. Trace whether the skewed join settings are recognized and applied; done means the issue has a confirmed cause and a verified correction or documented limitation.

Written by the indexing model from the issue text.

Assessment

Tech stack
scala, spark
Domain
data-engineering, distributed-systems, performance
Issue type
Bug
Difficulty
4/5
Estimated time
3-5 days
Activity status
Stale
Clarity
Needs clarification
Newbie friendliness
25/100

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