Saket Saurabh created HIVE-14199:
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Summary: Enable Bucket Pruning for ACID tables
Key: HIVE-14199
URL: https://issues.apache.org/jira/browse/HIVE-14199
Project: Hive
Issue Type: Improvement
Components: Transactions
Reporter: Saket Saurabh
Assignee: Saket Saurabh
Currently, ACID tables do not benefit from the bucket pruning feature
introduced in HIVE-11525. The reason for this has been the fact that bucket
pruning happens at split generation level and for ACID, traditionally the delta
files were never split. The parallelism for ACID was then restricted to the
number of buckets. There would be as many splits as the number of buckets and
each worker processing one split would inevitably read all the delta files for
that bucket, even when the query may have originally required only one of the
buckets to be read.
However, HIVE-14035 now enables even the delta files to be also split. What
this means is that now we have enough information at the split generation level
to determine appropriate buckets to process for the delta files. This can
efficiently allow us to prune unnecessary buckets for delta files and will lead
to good performance gain for a large number of selective queries on ACID tables.
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