GitHub user ravipesala opened a pull request:
https://github.com/apache/incubator-carbondata/pull/358
[WIP] Adding bucketing to carbon table loading
Bucketing is the useful feature when user wants to join big tables. And
also it is useful in driver level partition pruning to improve query
performance.
User can add buckets on any dimension column (except complex types) as
follows
```
CREATE TABLE test(user_id BIGINT, firstname STRING, lastname STRING)
CLUSTERED BY(user_id) INTO 32 BUCKETS;
```
In the above example column `user_id` is hash partitioned and creates 32
buckets/partitions files in carbondata. So while doing the join with other
table on bucketed column it can select same buckets and do the join with out
shuffling.
Carbon creates following folder structure, since carbon is already
supporting partitioning in its file format we can make use of it or we can move
the partitionid to file metadata. But if we the partitionId to metadata then
there would be complications in backward compatability.
dbName -> tableName - > Fact -> Part<id> ->Segment_id -> carbondatafiles
You can merge this pull request into a Git repository by running:
$ git pull https://github.com/ravipesala/incubator-carbondata bucket
Alternatively you can review and apply these changes as the patch at:
https://github.com/apache/incubator-carbondata/pull/358.patch
To close this pull request, make a commit to your master/trunk branch
with (at least) the following in the commit message:
This closes #358
----
commit 76b7da3662f09a8a38544514e44f01b2c17662a1
Author: ravipesala <[email protected]>
Date: 2016-11-27T11:28:55Z
Added partitioner
commit a2a42c8edb77ad0bfe4ec503523f00f33105a588
Author: ravipesala <[email protected]>
Date: 2016-11-27T16:59:39Z
Added bucketing in load
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