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author | Michael Armbrust <michael@databricks.com> | 2014-04-07 00:14:00 -0700 |
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committer | Reynold Xin <rxin@apache.org> | 2014-04-07 00:14:00 -0700 |
commit | accd0999f9cb6a449434d3fc5274dd469eeecab2 (patch) | |
tree | 6c1a73644c3af4aee9a60872bc58d0a1a2bc531a /docs/hardware-provisioning.md | |
parent | 87d0928a3301835705652c24a26096546597e156 (diff) | |
download | spark-accd0999f9cb6a449434d3fc5274dd469eeecab2.tar.gz spark-accd0999f9cb6a449434d3fc5274dd469eeecab2.tar.bz2 spark-accd0999f9cb6a449434d3fc5274dd469eeecab2.zip |
[SQL] SPARK-1371 Hash Aggregation Improvements
Given:
```scala
case class Data(a: Int, b: Int)
val rdd =
sparkContext
.parallelize(1 to 200)
.flatMap(_ => (1 to 50000).map(i => Data(i % 100, i)))
rdd.registerAsTable("data")
cacheTable("data")
```
Before:
```
SELECT COUNT(*) FROM data:[10000000]
16795.567ms
SELECT a, SUM(b) FROM data GROUP BY a
7536.436ms
SELECT SUM(b) FROM data
10954.1ms
```
After:
```
SELECT COUNT(*) FROM data:[10000000]
1372.175ms
SELECT a, SUM(b) FROM data GROUP BY a
2070.446ms
SELECT SUM(b) FROM data
958.969ms
```
Author: Michael Armbrust <michael@databricks.com>
Closes #295 from marmbrus/hashAgg and squashes the following commits:
ec63575 [Michael Armbrust] Add comment.
d0495a9 [Michael Armbrust] Use scaladoc instead.
b4a6887 [Michael Armbrust] Address review comments.
a2d90ba [Michael Armbrust] Capture child output statically to avoid issues with generators and serialization.
7c13112 [Michael Armbrust] Rewrite Aggregate operator to stream input and use projections. Remove unused local RDD functions implicits.
5096f99 [Michael Armbrust] Make HiveUDAF fields transient since object inspectors are not serializable.
6a4b671 [Michael Armbrust] Add option to avoid binding operators expressions automatically.
92cca08 [Michael Armbrust] Always include serialization debug info when running tests.
1279df2 [Michael Armbrust] Increase default number of partitions.
Diffstat (limited to 'docs/hardware-provisioning.md')
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