The change set is actually pretty small -- mostly whitespace changes. Admittedly this is a scary change due to the lack of tests to cover the ec2 scripts, and also because indentation actually impacts control flow in Python ...
Look at changes without whitespace diff here: https://github.com/apache/spark/pull/891/files?w=1
Author: Reynold Xin <rxin@apache.org>
Closes#891 from rxin/spark-ec2-pep8 and squashes the following commits:
ac1bf11 [Reynold Xin] Made spark_ec2.py PEP8 compliant.
...a JavaSparkContext and sqlCtx will refer to a JavaSQLContext
Author: Yadid Ayzenberg <yadid@media.mit.edu>
Closes#932 from yadid/master and squashes the following commits:
f92fb3a [Yadid Ayzenberg] updated java code blocks in spark SQL guide such that ctx will refer to a JavaSparkContext and sqlCtx will refer to a JavaSQLContext
https://issues.apache.org/jira/browse/SPARK-1917
Author: Uri Laserson <laserson@cloudera.com>
Closes#866 from laserson/SPARK-1917 and squashes the following commits:
d947e8c [Uri Laserson] Added test for scipy.special importing
1798bbd [Uri Laserson] SPARK-1917: fix PySpark import of scipy.special
Author: witgo <witgo@qq.com>
Closes#786 from witgo/maven_plugin and squashes the following commits:
5de86a2 [witgo] Merge branch 'master' of https://github.com/apache/spark into maven_plugin
c35ef73 [witgo] Improve maven plugin configuration
This patch simply ports over the Scala implementation of RDD#take(), which reads the first partition at the driver, then decides how many more partitions it needs to read and will possibly start a real job if it's more than 1. (Note that SparkContext#runJob(allowLocal=true) only runs the job locally if there's 1 partition selected and no parent stages.)
Author: Aaron Davidson <aaron@databricks.com>
Closes#922 from aarondav/take and squashes the following commits:
fa06df9 [Aaron Davidson] SPARK-1839: PySpark RDD#take() shouldn't always read from driver
`Properties#load()` doesn't close the InputStream, but it'd be closed after being GC'd anyway...
Also changed file.getName to file, because getName only shows the filename. This will show the full (possibly relative) path, which is less confusing if it's not found.
Author: Aaron Davidson <aaron@databricks.com>
Closes#914 from aarondav/tiny and squashes the following commits:
db9d072 [Aaron Davidson] Super minor: Close inputStream in SparkSubmitArguments
Author: Michael Armbrust <michael@databricks.com>
Closes#913 from marmbrus/timestampMetastore and squashes the following commits:
8e0154f [Michael Armbrust] Add timestamp to hive metastore type parser.
Due to the way spark-shell launches from an assembly jar, I don't think this change will affect anyone who isn't trying to launch the shell directly from sbt. That said, it is kinda nice to be able to launch all things directly from SBT when developing.
Author: Michael Armbrust <michael@databricks.com>
Closes#801 from marmbrus/hiveRepl and squashes the following commits:
9570571 [Michael Armbrust] Optionally include Hive as a dependency of the REPL.
Child of `SumDistinct` or `Average` should be widened to prevent overflows the same as `Sum`.
Author: Takuya UESHIN <ueshin@happy-camper.st>
Closes#902 from ueshin/issues/SPARK-1947 and squashes the following commits:
99c3dcb [Takuya UESHIN] Insert Cast for SumDistinct and Average.
Author: Chen Chao <crazyjvm@gmail.com>
Closes#928 from CrazyJvm/patch-8 and squashes the following commits:
144328b [Chen Chao] correct tiny comment error
JIRA issue: [SPARK-1959](https://issues.apache.org/jira/browse/SPARK-1959)
Author: Cheng Lian <lian.cs.zju@gmail.com>
Closes#909 from liancheng/spark-1959 and squashes the following commits:
306659c [Cheng Lian] [SPARK-1959] String "NULL" shouldn't be interpreted as null value
Spark streaming requires at least two working threads, but the document gives the example like
import org.apache.spark.api.java.function._
import org.apache.spark.streaming._
import org.apache.spark.streaming.api._
// Create a StreamingContext with a local master
val ssc = new StreamingContext("local", "NetworkWordCount", Seconds(1))
http://spark.apache.org/docs/latest/streaming-programming-guide.html
Author: CodingCat <zhunansjtu@gmail.com>
Closes#924 from CodingCat/master and squashes the following commits:
bb89f20 [CodingCat] update streaming docs
Author: nchammas <nicholas.chammas@gmail.com>
Closes#923 from nchammas/patch-1 and squashes the following commits:
65c4d18 [nchammas] updated link to mailing list
https://issues.apache.org/jira/browse/SPARK-1901
Author: Zhen Peng <zhenpeng01@baidu.com>
Closes#854 from zhpengg/bugfix-worker-kills-executor and squashes the following commits:
21d380b [Zhen Peng] add some error messages
506cea6 [Zhen Peng] add some docs for killProcess()
a0b9860 [Zhen Peng] [SPARK-1901] worker should make sure executor has exited before updating executor's info
Author: Prashant Sharma <prashant.s@imaginea.com>
Closes#910 from ScrapCodes/enable-mima/spark-core and squashes the following commits:
79f3687 [Prashant Sharma] updated Mima to check against version 1.0
1e8969c [Prashant Sharma] Spark core missed out on Mima settings. So in effect we never tested spark core for mima related errors.
This is a fairly large PR to clean up and update the docs for 1.0. The major changes are:
* A unified programming guide for all languages replaces language-specific ones and shows language-specific info in tabs
* New programming guide sections on key-value pairs, unit testing, input formats beyond text, migrating from 0.9, and passing functions to Spark
* Spark-submit guide moved to a separate page and expanded slightly
* Various cleanups of the menu system, security docs, and others
* Updated look of title bar to differentiate the docs from previous Spark versions
You can find the updated docs at http://people.apache.org/~matei/1.0-docs/_site/ and in particular http://people.apache.org/~matei/1.0-docs/_site/programming-guide.html.
Author: Matei Zaharia <matei@databricks.com>
Closes#896 from mateiz/1.0-docs and squashes the following commits:
03e6853 [Matei Zaharia] Some tweaks to configuration and YARN docs
0779508 [Matei Zaharia] tweak
ef671d4 [Matei Zaharia] Keep frames in JavaDoc links, and other small tweaks
1bf4112 [Matei Zaharia] Review comments
4414f88 [Matei Zaharia] tweaks
d04e979 [Matei Zaharia] Fix some old links to Java guide
a34ed33 [Matei Zaharia] tweak
541bb3b [Matei Zaharia] miscellaneous changes
fcefdec [Matei Zaharia] Moved submitting apps to separate doc
61d72b4 [Matei Zaharia] stuff
181f217 [Matei Zaharia] migration guide, remove old language guides
e11a0da [Matei Zaharia] Add more API functions
6a030a9 [Matei Zaharia] tweaks
8db0ae3 [Matei Zaharia] Added key-value pairs section
318d2c9 [Matei Zaharia] tweaks
1c81477 [Matei Zaharia] New section on basics and function syntax
e38f559 [Matei Zaharia] Actually added programming guide to Git
a33d6fe [Matei Zaharia] First pass at updating programming guide to support all languages, plus other tweaks throughout
3b6a876 [Matei Zaharia] More CSS tweaks
01ec8bf [Matei Zaharia] More CSS tweaks
e6d252e [Matei Zaharia] Change color of doc title bar to differentiate from 0.9.0
We add all the classes annotated as `DeveloperApi` to `~/.mima-excludes`.
Author: Prashant Sharma <prashant.s@imaginea.com>
Author: nikhil7sh <nikhilsharmalnmiit@gmail.ccom>
Closes#904 from ScrapCodes/SPARK-1820/ignore-Developer-Api and squashes the following commits:
de944f9 [Prashant Sharma] Code review.
e3c5215 [Prashant Sharma] Incorporated patrick's suggestions and fixed the scalastyle build.
9983a42 [nikhil7sh] [SPARK-1820] Make GenerateMimaIgnore @DeveloperApi annotation aware
A straightforward implementation of LPA algorithm for detecting graph communities using the Pregel framework. Amongst the growing literature on community detection algorithms in networks, LPA is perhaps the most elementary, and despite its flaws it remains a nice and simple approach.
Author: Ankur Dave <ankurdave@gmail.com>
Author: haroldsultan <haroldsultan@gmail.com>
Author: Harold Sultan <haroldsultan@gmail.com>
Closes#905 from haroldsultan/master and squashes the following commits:
327aee0 [haroldsultan] Merge pull request #2 from ankurdave/label-propagation
227a4d0 [Ankur Dave] Untabify
0ac574c [haroldsultan] Merge pull request #1 from ankurdave/label-propagation
0e24303 [Ankur Dave] Add LabelPropagationSuite
84aa061 [Ankur Dave] LabelPropagation: Fix compile errors and style; rename from LPA
9830342 [Harold Sultan] initial version of LPA
JIRA issue: [SPARK-1368](https://issues.apache.org/jira/browse/SPARK-1368)
This PR introduces two major updates:
- Replaced FP style code with `while` loop and reusable `GenericMutableRow` object in critical path of `HiveTableScan`.
- Using `ColumnProjectionUtils` to help optimizing RCFile and ORC column pruning.
My quick micro benchmark suggests these two optimizations made the optimized version 2x and 2.5x faster when scanning CSV table and RCFile table respectively:
```
Original:
[info] CSV: 27676 ms, RCFile: 26415 ms
[info] CSV: 27703 ms, RCFile: 26029 ms
[info] CSV: 27511 ms, RCFile: 25962 ms
Optimized:
[info] CSV: 13820 ms, RCFile: 10402 ms
[info] CSV: 14158 ms, RCFile: 10691 ms
[info] CSV: 13606 ms, RCFile: 10346 ms
```
The micro benchmark loads a 609MB CVS file (structurally similar to the `src` test table) into a normal Hive table with `LazySimpleSerDe` and a RCFile table, then scans these tables respectively.
Preparation code:
```scala
package org.apache.spark.examples.sql.hive
import org.apache.spark.sql.hive.LocalHiveContext
import org.apache.spark.{SparkConf, SparkContext}
object HiveTableScanPrepare extends App {
val sparkContext = new SparkContext(
new SparkConf()
.setMaster("local")
.setAppName(getClass.getSimpleName.stripSuffix("$")))
val hiveContext = new LocalHiveContext(sparkContext)
import hiveContext._
hql("drop table scan_csv")
hql("drop table scan_rcfile")
hql("""create table scan_csv (key int, value string)
| row format serde 'org.apache.hadoop.hive.serde2.lazy.LazySimpleSerDe'
| with serdeproperties ('field.delim'=',')
""".stripMargin)
hql(s"""load data local inpath "${args(0)}" into table scan_csv""")
hql("""create table scan_rcfile (key int, value string)
| row format serde 'org.apache.hadoop.hive.serde2.columnar.ColumnarSerDe'
|stored as
| inputformat 'org.apache.hadoop.hive.ql.io.RCFileInputFormat'
| outputformat 'org.apache.hadoop.hive.ql.io.RCFileOutputFormat'
""".stripMargin)
hql(
"""
|from scan_csv
|insert overwrite table scan_rcfile
|select scan_csv.key, scan_csv.value
""".stripMargin)
}
```
Benchmark code:
```scala
package org.apache.spark.examples.sql.hive
import org.apache.spark.sql.hive.LocalHiveContext
import org.apache.spark.{SparkConf, SparkContext}
object HiveTableScanBenchmark extends App {
val sparkContext = new SparkContext(
new SparkConf()
.setMaster("local")
.setAppName(getClass.getSimpleName.stripSuffix("$")))
val hiveContext = new LocalHiveContext(sparkContext)
import hiveContext._
val scanCsv = hql("select key from scan_csv")
val scanRcfile = hql("select key from scan_rcfile")
val csvDuration = benchmark(scanCsv.count())
val rcfileDuration = benchmark(scanRcfile.count())
println(s"CSV: $csvDuration ms, RCFile: $rcfileDuration ms")
def benchmark(f: => Unit) = {
val begin = System.currentTimeMillis()
f
val end = System.currentTimeMillis()
end - begin
}
}
```
@marmbrus Please help review, thanks!
Author: Cheng Lian <lian.cs.zju@gmail.com>
Closes#758 from liancheng/fastHiveTableScan and squashes the following commits:
4241a19 [Cheng Lian] Distinguishes sorted and possibly not sorted operations more accurately in HiveComparisonTest
cf640d8 [Cheng Lian] More HiveTableScan optimisations:
bf0e7dc [Cheng Lian] Added SortedOperation pattern to match *some* definitely sorted operations and avoid some sorting cost in HiveComparisonTest.
6d1c642 [Cheng Lian] Using ColumnProjectionUtils to optimise RCFile and ORC column pruning
eb62fd3 [Cheng Lian] [SPARK-1368] Optimized HiveTableScan
Author: Yin Huai <huai@cse.ohio-state.edu>
Closes#889 from yhuai/SPARK-1935 and squashes the following commits:
7d50ef1 [Yin Huai] Explicitly add commons-codec 1.5 as a dependency.
Added doctest for method textFile and description for methods _initialize_context and _ensure_initialized in context.py
Author: Jyotiska NK <jyotiska123@gmail.com>
Closes#187 from jyotiska/pyspark_context and squashes the following commits:
356f945 [Jyotiska NK] Added doctest for textFile method in context.py
5b23686 [Jyotiska NK] Updated context.py with method descriptions
The changes could be ported back to 0.9 as well.
Changing in.read to in.readFully to read the whole input stream rather than the first 1020 bytes.
This should ok considering that Flume caps the body size to 32K by default.
Author: David Lemieux <david.lemieux@radialpoint.com>
Closes#865 from lemieud/SPARK-1916 and squashes the following commits:
a265673 [David Lemieux] Updated SparkFlumeEvent to read the whole stream rather than the first X bytes.
(cherry picked from commit 0b769b73fb)
Signed-off-by: Patrick Wendell <pwendell@gmail.com>
This PR improves and organizes the config option page
and makes a few other changes to config docs. See a preview here:
http://people.apache.org/~pwendell/config-improvements/configuration.html
The biggest changes are:
1. The configs for the standalone master/workers were moved to the
standalone page and out of the general config doc.
2. SPARK_LOCAL_DIRS was missing from the standalone docs.
3. Expanded discussion of injecting configs with spark-submit, including an
example.
4. Config options were organized into the following categories:
- Runtime Environment
- Shuffle Behavior
- Spark UI
- Compression and Serialization
- Execution Behavior
- Networking
- Scheduling
- Security
- Spark Streaming
Author: Patrick Wendell <pwendell@gmail.com>
Closes#880 from pwendell/config-cleanup and squashes the following commits:
93f56c3 [Patrick Wendell] Feedback from Matei
6f66efc [Patrick Wendell] More feedback
16ae776 [Patrick Wendell] Adding back header section
d9c264f [Patrick Wendell] Small fix
e0c1728 [Patrick Wendell] Response to Matei's review
27d57db [Patrick Wendell] Reverting changes to index.html (covered in #896)
e230ef9 [Patrick Wendell] Merge remote-tracking branch 'apache/master' into config-cleanup
a374369 [Patrick Wendell] Line wrapping fixes
fdff7fc [Patrick Wendell] Merge remote-tracking branch 'apache/master' into config-cleanup
3289ea4 [Patrick Wendell] Pulling in changes from #856
106ee31 [Patrick Wendell] Small link fix
f7e79bc [Patrick Wendell] Re-organizing config options.
54b184d [Patrick Wendell] Adding standalone configs to the standalone page
592e94a [Patrick Wendell] Stash
29b5446 [Patrick Wendell] Better discussion of spark-submit in configuration docs
2d719ef [Patrick Wendell] Small fix
4af9e07 [Patrick Wendell] Adding SPARK_LOCAL_DIRS docs
204b248 [Patrick Wendell] Small fixes
`ApproxCountDistinctMergeFunction` should return `Int` value because the `dataType` of `ApproxCountDistinct` is `IntegerType`.
Author: Takuya UESHIN <ueshin@happy-camper.st>
Closes#893 from ueshin/issues/SPARK-1938 and squashes the following commits:
3970e88 [Takuya UESHIN] Remove a superfluous line.
5ad7ec1 [Takuya UESHIN] Make dataType for each of CountDistinct, ApproxCountDistinctMerge and ApproxCountDistinct LongType.
cbe7c71 [Takuya UESHIN] Revert a change.
fc3ac0f [Takuya UESHIN] Fix evaluated value type of ApproxCountDistinctMergeFunction to Int.
Allow underscore in column name of a struct field https://issues.apache.org/jira/browse/SPARK-1922 .
Author: LY Lai <ly.lai@vpon.com>
Closes#873 from lyuanlai/master and squashes the following commits:
2253263 [LY Lai] Allow underscore in struct field column name
Average values are difference between the calculation is done partially or not partially.
Because `AverageFunction` (in not-partially calculation) counts even if the evaluated value is null.
Author: Takuya UESHIN <ueshin@happy-camper.st>
Closes#862 from ueshin/issues/SPARK-1915 and squashes the following commits:
b1ff3c0 [Takuya UESHIN] Modify AverageFunction not to count if the evaluated value is null.
Nullability of `Max`/`Min`/`First` should be `true` because they return `null` if there are no rows.
Author: Takuya UESHIN <ueshin@happy-camper.st>
Closes#881 from ueshin/issues/SPARK-1926 and squashes the following commits:
322610f [Takuya UESHIN] Fix nullability of Min/Max/First.
bugfix worker DriverStateChanged state should match DriverState.FAILED
Author: lianhuiwang <lianhuiwang09@gmail.com>
Closes#864 from lianhuiwang/master and squashes the following commits:
480ce94 [lianhuiwang] address aarondav comments
f2b5970 [lianhuiwang] bugfix worker DriverStateChanged state should match DriverState.FAILED
`var cachedPeers: Seq[BlockManagerId] = null` is used in `def replicate(blockId: BlockId, data: ByteBuffer, level: StorageLevel)` without proper protection.
There are two place will call `replicate(blockId, bytesAfterPut, level)`
* 17f3075bc4/core/src/main/scala/org/apache/spark/storage/BlockManager.scala (L644) runs in `connectionManager.futureExecContext`
* 17f3075bc4/core/src/main/scala/org/apache/spark/storage/BlockManager.scala (L752) `doPut` runs in `connectionManager.handleMessageExecutor`. `org.apache.spark.storage.BlockManagerWorker` calls `blockManager.putBytes` in `connectionManager.handleMessageExecutor`.
As they run in different `Executor`s, this is a race condition which may cause the memory pointed by `cachedPeers` is not correct even if `cachedPeers != null`.
The race condition of `onReceiveCallback` is that it's set in `BlockManagerWorker` but read in a different thread in `ConnectionManager.handleMessageExecutor`.
Author: zsxwing <zsxwing@gmail.com>
Closes#887 from zsxwing/SPARK-1932 and squashes the following commits:
524f69c [zsxwing] SPARK-1932: Fix race conditions in onReceiveCallback and cachedPeers
https://issues.apache.org/jira/browse/SPARK-1933
Author: Reynold Xin <rxin@apache.org>
Closes#888 from rxin/addfile and squashes the following commits:
8c402a3 [Reynold Xin] Updated comment.
ff6c162 [Reynold Xin] SPARK-1933: Throw a more meaningful exception when a directory is passed to addJar/addFile.
Author: Reynold Xin <rxin@apache.org>
Closes#875 from rxin/pep8-dev-scripts and squashes the following commits:
04b084f [Reynold Xin] Made dev Python scripts PEP8 compliant.
DAGScheduler does not handle local task OOM properly, and will wait for the job result forever.
Author: Zhen Peng <zhenpeng01@baidu.com>
Closes#883 from zhpengg/bugfix-dag-scheduler-oom and squashes the following commits:
76f7eda [Zhen Peng] remove redundant memory allocations
aa63161 [Zhen Peng] SPARK-1929 DAGScheduler suspended by local task OOM
905173df57 introduced a bug in partitionBy where, after repartitioning the edges, it reuses the VertexRDD without updating the routing tables to reflect the new edge layout. Subsequent accesses of the triplets contain nulls for many vertex properties.
This commit adds a test for this bug and fixes it by introducing `VertexRDD#withEdges` and calling it in `partitionBy`.
Author: Ankur Dave <ankurdave@gmail.com>
Closes#885 from ankurdave/SPARK-1931 and squashes the following commits:
3930cdd [Ankur Dave] Note how to set up VertexRDD for efficient joins
9bdbaa4 [Ankur Dave] [SPARK-1931] Reconstruct routing tables in Graph.partitionBy
JIRA: https://issues.apache.org/jira/browse/SPARK-1925
Author: zsxwing <zsxwing@gmail.com>
Closes#879 from zsxwing/SPARK-1925 and squashes the following commits:
5cf5a6d [zsxwing] SPARK-1925: Replace '&' with '&&'
Author: witgo <witgo@qq.com>
Closes#884 from witgo/scalastyle and squashes the following commits:
4b08ae4 [witgo] Fix scalastyle warnings in yarn alpha
`CountFunction` should count up only if the child's evaluated value is not null.
Because it traverses to evaluate all child expressions, even if the child is null, it counts up if one of the all children is not null.
Author: Takuya UESHIN <ueshin@happy-camper.st>
Closes#861 from ueshin/issues/SPARK-1914 and squashes the following commits:
3b37315 [Takuya UESHIN] Merge branch 'master' into issues/SPARK-1914
2afa238 [Takuya UESHIN] Simplify CountFunction not to traverse to evaluate all child expressions.
Self explanatory.
Author: Patrick Wendell <pwendell@gmail.com>
Closes#878 from pwendell/java-constructor and squashes the following commits:
2cc1605 [Patrick Wendell] HOTFIX: Add no-arg SparkContext constructor in Java
```scala
rdd.aggregate(Sum('val))
```
is just shorthand for
```scala
rdd.groupBy()(Sum('val))
```
but seems be more natural than doing a groupBy with no grouping expressions when you really just want an aggregation over all rows.
Did not add a JavaSchemaRDD or Python API, as these seem to be lacking several other methods like groupBy() already -- leaving that cleanup for future patches.
Author: Aaron Davidson <aaron@databricks.com>
Closes#874 from aarondav/schemardd and squashes the following commits:
e9e68ee [Aaron Davidson] Add comment
db6afe2 [Aaron Davidson] Introduce SchemaRDD#aggregate() for simple aggregations
https://issues.apache.org/jira/browse/SPARK-1903
Author: Andrew Ash <andrew@andrewash.com>
Closes#856 from ash211/SPARK-1903 and squashes the following commits:
6e7782a [Andrew Ash] Add the technology used on each port
1d9b5d3 [Andrew Ash] Document port for history server
56193ee [Andrew Ash] spark.ui.port becomes worker.ui.port and master.ui.port
a774c07 [Andrew Ash] Wording in network section
90e8237 [Andrew Ash] Use real :toc instead of the hand-written one
edaa337 [Andrew Ash] Master -> Standalone Cluster Master
57e8869 [Andrew Ash] Port -> Default Port
3d4d289 [Andrew Ash] Title to title case
c7d42d9 [Andrew Ash] [WIP] SPARK-1903 Add initial port listing for documentation
a416ae9 [Andrew Ash] Word wrap to 100 lines
Author: Reynold Xin <rxin@apache.org>
Closes#871 from rxin/mllib-pep8 and squashes the following commits:
848416f [Reynold Xin] Fixed a typo in the previous cleanup (c -> sc).
a8db4cd [Reynold Xin] Fix PEP8 violations in Python mllib.
Mostly related to the following two rules in PEP8 and PEP257:
- Line length < 72 chars.
- First line should be a concise description of the function/class.
Author: Reynold Xin <rxin@apache.org>
Closes#869 from rxin/docstring-schemardd and squashes the following commits:
7cf0cbc [Reynold Xin] Updated sql.py for pep8 docstring.
0a4aef9 [Reynold Xin] Merge branch 'master' into docstring-schemardd
6678937 [Reynold Xin] Python docstring update for sql.py.
Author: Reynold Xin <rxin@apache.org>
Closes#870 from rxin/examples-python-pep8 and squashes the following commits:
2829e84 [Reynold Xin] Fix PEP8 violations in examples/src/main/python.
Minor cleanup following #841.
Author: Reynold Xin <rxin@apache.org>
Closes#868 from rxin/schema-count and squashes the following commits:
5442651 [Reynold Xin] SPARK-1822: Some minor cleanup work on SchemaRDD.count()
This sets the max line length to 100 as a PEP8 exception.
Author: Reynold Xin <rxin@apache.org>
Closes#872 from rxin/pep8 and squashes the following commits:
2f26029 [Reynold Xin] Added PEP8 style configuration file.
Author: Kan Zhang <kzhang@apache.org>
Closes#841 from kanzhang/SPARK-1822 and squashes the following commits:
2f8072a [Kan Zhang] [SPARK-1822] Minor style update
cf4baa4 [Kan Zhang] [SPARK-1822] Adding Scaladoc
e67c910 [Kan Zhang] [SPARK-1822] SchemaRDD.count() should use optimizer
