Avoid dynamic dispatching when unwrapping Hive data.

This is a follow up of PR #758.

The `unwrapHiveData` function is now composed statically before actual rows are scanned according to the field object inspector to avoid dynamic dispatching cost.

According to the same micro benchmark used in PR #758, this simple change brings slight performance boost: 2.5% for CSV table and 1% for RCFile table.

```
Optimized version:

CSV: 6870 ms, RCFile: 5687 ms
CSV: 6832 ms, RCFile: 5800 ms
CSV: 6822 ms, RCFile: 5679 ms
CSV: 6704 ms, RCFile: 5758 ms
CSV: 6819 ms, RCFile: 5725 ms

Original version:

CSV: 7042 ms, RCFile: 5667 ms
CSV: 6883 ms, RCFile: 5703 ms
CSV: 7115 ms, RCFile: 5665 ms
CSV: 7020 ms, RCFile: 5981 ms
CSV: 6871 ms, RCFile: 5906 ms
```

Author: Cheng Lian <lian.cs.zju@gmail.com>

Closes #935 from liancheng/staticUnwrapping and squashes the following commits:

c49c70c [Cheng Lian] Avoid dynamic dispatching when unwrapping Hive data.

(cherry picked from commit 862283e9ccace6824880aa4e161723fb3248d438)
Signed-off-by: Michael Armbrust <michael@databricks.com>
SPARK-2001 : Remove docs/spark-debugger.md from master

Per discussion in dev list:
"
Seemed like the spark-debugger.md is no longer accurate (see
http://spark.apache.org/docs/latest/spark-debugger.html) and since it
was originally written Spark has evolved that makes the doc obsolete.
There are already work pending for new replay debugging (I could not
find the PR links for it) so I
With version control we could always reinstate the old doc if needed,
but as of today the doc is no longer reflect the current state of
Spark's RDD.
"

Author: Henry Saputra <henry.saputra@gmail.com>

Closes #953 from hsaputra/SPARK-2001-hsaputra and squashes the following commits:

dc324aa [Henry Saputra] SPARK-2001 : Remove docs/spark-debugger.md from master since it is obsolete

(cherry picked from commit 6c044ed100081f1fa7c8df4bd4b58b65a61c3360)
Signed-off-by: Reynold Xin <rxin@apache.org>
Add support for Pivotal HD in the Maven build: SPARK-1992

Allow Spark to build against particular Pivotal HD distributions. For example to build Spark against Pivotal HD 2.0.1 one can run:
```
mvn -Pyarn -Phadoop-2.2 -Dhadoop.version=2.2.0-gphd-3.0.1.0 -DskipTests clean package
```

Author: tzolov <christian.tzolov@gmail.com>

Closes #942 from tzolov/master and squashes the following commits:

bc3e05a [tzolov] Add support for Pivotal HD in the Maven build and SBT build: [SPARK-1992]

(cherry picked from commit b1f285359a12345d94ae59f979d9a75482e732ce)
Signed-off-by: Matei Zaharia <matei@databricks.com>
[SPARK-1468] Modify the partition function used by partitionBy.

Make partitionBy use a tweaked version of hash as its default partition function
since the python hash function does not consistently assign the same value
to None across python processes.

Associated JIRA at https://issues.apache.org/jira/browse/SPARK-1468

Author: Erik Selin <erik.selin@jadedpixel.com>

Closes #371 from tyro89/consistent_hashing and squashes the following commits:

201c301 [Erik Selin] Make partitionBy use a tweaked version of hash as its default partition function since the python hash function does not consistently assign the same value to None across python processes.

(cherry picked from commit 8edc9d0330c94b50e01956ae88693cff4e0977b2)
Signed-off-by: Matei Zaharia <matei@databricks.com>
fix java.lang.ClassCastException

get Exception when run：bin/run-example org.apache.spark.examples.sql.RDDRelation
Exception's detail is:
Exception in thread "main" java.lang.ClassCastException: java.lang.Long cannot be cast to java.lang.Integer
	at scala.runtime.BoxesRunTime.unboxToInt(BoxesRunTime.java:106)
	at org.apache.spark.sql.catalyst.expressions.GenericRow.getInt(Row.scala:145)
	at org.apache.spark.examples.sql.RDDRelation$.main(RDDRelation.scala:49)
	at org.apache.spark.examples.sql.RDDRelation.main(RDDRelation.scala)
change sql("SELECT COUNT(*) FROM records").collect().head.getInt(0) to sql("SELECT COUNT(*) FROM records").collect().head.getLong(0), then the Exception do not occur any more

Author: baishuo(白硕) <vc_java@hotmail.com>

Closes #949 from baishuo/master and squashes the following commits:

f4b319f [baishuo(白硕)] fix java.lang.ClassCastException

(cherry picked from commit aa41a522d821c989c65fa3f7f2a4d372e39bb958)
Signed-off-by: Michael Armbrust <michael@databricks.com>
SPARK-1518: FileLogger: Fix compile against Hadoop trunk

In Hadoop trunk (currently Hadoop 3.0.0), the deprecated
FSDataOutputStream#sync() method has been removed.  Instead, we should
call FSDataOutputStream#hflush, which does the same thing as the
deprecated method used to do.

Author: Colin McCabe <cmccabe@cloudera.com>

Closes #898 from cmccabe/SPARK-1518 and squashes the following commits:

752b9d7 [Colin McCabe] FileLogger: Fix compile against Hadoop trunk
(cherry picked from commit 1765c8d0ddf6bb5bc3c21f994456eba04c581de4)

Signed-off-by: Patrick Wendell <pwendell@gmail.com>
SPARK-1790: Update EC2 scripts to support r3 instance types

Author: Varakhedi Sujeet <svarakhedi@gopivotal.com>

Closes #960 from sujeetv/ec2-r3 and squashes the following commits:

3cb9fd5 [Varakhedi Sujeet] SPARK-1790: Update EC2 scripts to support r3 instance
(cherry picked from commit 11ded3f66f178e4d8d2b23491dd5e0ea23bcf719)

Conflicts:

	ec2/spark_ec2.py
[SPARK-2030] Bump SparkBuild.scala version number of branch-1.0 to 1.0.1-SNAPSHOT.

Author: Takuya UESHIN <ueshin@happy-camper.st>

Closes #975 from ueshin/issues/SPARK-2030 and squashes the following commits:

aae1044 [Takuya UESHIN] Bump version number to 1.0.1-SNAPSHOT.
SPARK-1677: allow user to disable output dir existence checking

https://issues.apache.org/jira/browse/SPARK-1677

For compatibility with older versions of Spark it would be nice to have an option `spark.hadoop.validateOutputSpecs` (default true)  for the user to disable the output directory existence checking

Author: CodingCat <zhunansjtu@gmail.com>

Closes #947 from CodingCat/SPARK-1677 and squashes the following commits:

7930f83 [CodingCat] miao
c0c0e03 [CodingCat] bug fix and doc update
5318562 [CodingCat] bug fix
13219b5 [CodingCat] allow user to disable output dir existence checking
(cherry picked from commit 89cdbb087cb2f0d03be2dd77440300c6bd61c792)

Signed-off-by: Patrick Wendell <pwendell@gmail.com>
[SPARK-2036] [SQL] CaseConversionExpression should check if the evaluated value is null.

`CaseConversionExpression` should check if the evaluated value is `null`.

Author: Takuya UESHIN <ueshin@happy-camper.st>

Closes #982 from ueshin/issues/SPARK-2036 and squashes the following commits:

61e1c54 [Takuya UESHIN] Add check if the evaluated value is null.

(cherry picked from commit e4c11eef2f64df0b6a432f40b669486d91ca6352)
Signed-off-by: Michael Armbrust <michael@databricks.com>
[SPARK-2041][SQL] Correctly analyze queries where columnName == tableName.

Author: Michael Armbrust <michael@databricks.com>

Closes #985 from marmbrus/tableName and squashes the following commits:

3caaa27 [Michael Armbrust] Correctly analyze queries where columnName == tableName.

(cherry picked from commit c7a183b2c2bca13565496495b4ae3a3a9f63f9ab)
Signed-off-by: Reynold Xin <rxin@apache.org>
[SPARK-2025] Unpersist edges of previous graph in Pregel

Due to a bug introduced by apache/spark#497, Pregel does not unpersist replicated vertices from previous iterations. As a result, they stay cached until memory is full, wasting GC time.

This PR corrects the problem by unpersisting both the edges and the replicated vertices of previous iterations. This is safe because the edges and replicated vertices of the current iteration are cached by the call to `g.cache()` and then materialized by the call to `messages.count()`. Therefore no unmaterialized RDDs depend on `prevG.edges`. I verified that no recomputation occurs by running PageRank with a custom patch to Spark that warns when a partition is recomputed.

Thanks to Tim Weninger for reporting this bug.

Author: Ankur Dave <ankurdave@gmail.com>

Closes #972 from ankurdave/SPARK-2025 and squashes the following commits:

13d5b07 [Ankur Dave] Unpersist edges of previous graph in Pregel

(cherry picked from commit 9bad0b73722fb359f14db864e69aa7efde3588c5)
Signed-off-by: Reynold Xin <rxin@apache.org>
SPARK-2043: ExternalAppendOnlyMap doesn't always find matching keys

The current implementation reads one key with the next hash code as it finishes reading the keys with the current hash code, which may cause it to miss some matches of the next key. This can cause operations like join to give the wrong result when reduce tasks spill to disk and there are hash collisions, as values won't be matched together. This PR fixes it by not reading in that next key, using a peeking iterator instead.

Author: Matei Zaharia <matei@databricks.com>

Closes #986 from mateiz/spark-2043 and squashes the following commits:

0959514 [Matei Zaharia] Added unit test for having many hash collisions
892debb [Matei Zaharia] SPARK-2043: don't read a key with the next hash code in ExternalAppendOnlyMap, instead use a buffered iterator to only read values with the current hash code.

(cherry picked from commit b45c13e7d798f97b92f1a6329528191b8d779c4f)
Signed-off-by: Matei Zaharia <matei@databricks.com>
[SPARK-2050][SQL] LIKE, RLIKE and IN in HQL should not be case sensitive.

Author: Michael Armbrust <michael@databricks.com>

Closes #989 from marmbrus/caseSensitiveFuncitons and squashes the following commits:

681de54 [Michael Armbrust] LIKE, RLIKE and IN in HQL should not be case sensitive.

(cherry picked from commit 41db44c428a10f4453462d002d226798bb8fbdda)
Signed-off-by: Reynold Xin <rxin@apache.org>
[SPARK-2050 - 2][SQL] DIV and BETWEEN should not be case sensitive.

Followup: #989

Author: Michael Armbrust <michael@databricks.com>

Closes #994 from marmbrus/caseSensitiveFunctions2 and squashes the following commits:

9d9c8ed [Michael Armbrust] Fix DIV and BETWEEN.

(cherry picked from commit 8d210560be8b143e48abfbaca347f383b5aa4798)
Signed-off-by: Michael Armbrust <michael@databricks.com>
[SPARK-1994][SQL] Weird data corruption bug when running Spark SQL on data in HDFS

Basically there is a race condition (possibly a scala bug?) when these values are recomputed on all of the slaves that results in an incorrect projection being generated (possibly because the GUID uniqueness contract is broken?).

In general we should probably enforce that all expression planing occurs on the driver, as is now occurring here.

Author: Michael Armbrust <michael@databricks.com>

Closes #1004 from marmbrus/fixAggBug and squashes the following commits:

e0c116c [Michael Armbrust] Compute aggregate expression during planning instead of lazily on workers.

(cherry picked from commit a6c72ab16e7a3027739ab419819f5222e270838e)
Signed-off-by: Reynold Xin <rxin@apache.org>
Update run-example

Old code can only be ran under spark_home and use "bin/run-example".
 Error "./run-example: line 55: ./bin/spark-submit: No such file or directory" appears when running in other place. So change this

Author: maji2014 <maji3@asiainfo-linkage.com>

Closes #1011 from maji2014/master and squashes the following commits:

2cc1af6 [maji2014] Update run-example

Closes #988.
(cherry picked from commit e9261d0866a610eab29fa332726186b534d1018f)

Signed-off-by: Patrick Wendell <pwendell@gmail.com>
[SPARK-2067] use relative path for Spark logo in UI

Author: Neville Li <neville@spotify.com>

Closes #1006 from nevillelyh/gh/SPARK-2067 and squashes the following commits:

9ee64cf [Neville Li] [SPARK-2067] use relative path for Spark logo in UI
(cherry picked from commit 15ddbef414d5fd6d4672936ba3c747b5fb7ab52b)

Signed-off-by: Patrick Wendell <pwendell@gmail.com>
SPARK-1944 Document --verbose in spark-shell -h

https://issues.apache.org/jira/browse/SPARK-1944

Author: Andrew Ash <andrew@andrewash.com>

Closes #1020 from ash211/SPARK-1944 and squashes the following commits:

a831c4d [Andrew Ash] SPARK-1944 Document --verbose in spark-shell -h

(cherry picked from commit 35630c86ff0e27862c9d902887eb0a24d25867ae)
Signed-off-by: Reynold Xin <rxin@apache.org>
[SPARK-1495][SQL]add support for left semi join

Just submit another solution for #395

Author: Daoyuan <daoyuan.wang@intel.com>
Author: Michael Armbrust <michael@databricks.com>
Author: Daoyuan Wang <daoyuan.wang@intel.com>

Closes #837 from adrian-wang/left-semi-join-support and squashes the following commits:

d39cd12 [Daoyuan Wang] Merge pull request #1 from marmbrus/pr/837
6713c09 [Michael Armbrust] Better debugging for failed query tests.
035b73e [Michael Armbrust] Add test for left semi that can't be done with a hash join.
5ec6fa4 [Michael Armbrust] Add left semi to SQL Parser.
4c726e5 [Daoyuan] improvement according to Michael
8d4a121 [Daoyuan] add golden files for leftsemijoin
83a3c8a [Daoyuan] scala style fix
14cff80 [Daoyuan] add support for left semi join

(cherry picked from commit 0cf600280167a94faec75736223256e8f2e48085)
Signed-off-by: Michael Armbrust <michael@databricks.com>