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Posted to commits@spark.apache.org by ho...@apache.org on 2017/07/10 22:21:08 UTC

spark git commit: [SPARK-13534][PYSPARK] Using Apache Arrow to increase performance of DataFrame.toPandas

Repository: spark
Updated Branches:
  refs/heads/master 2bfd5accd -> d03aebbe6


[SPARK-13534][PYSPARK] Using Apache Arrow to increase performance of DataFrame.toPandas

## What changes were proposed in this pull request?
Integrate Apache Arrow with Spark to increase performance of `DataFrame.toPandas`.  This has been done by using Arrow to convert data partitions on the executor JVM to Arrow payload byte arrays where they are then served to the Python process.  The Python DataFrame can then collect the Arrow payloads where they are combined and converted to a Pandas DataFrame.  Data types except complex, date, timestamp, and decimal  are currently supported, otherwise an `UnsupportedOperation` exception is thrown.

Additions to Spark include a Scala package private method `Dataset.toArrowPayload` that will convert data partitions in the executor JVM to `ArrowPayload`s as byte arrays so they can be easily served.  A package private class/object `ArrowConverters` that provide data type mappings and conversion routines.  In Python, a private method `DataFrame._collectAsArrow` is added to collect Arrow payloads and a SQLConf "spark.sql.execution.arrow.enable" can be used in `toPandas()` to enable using Arrow (uses the old conversion by default).

## How was this patch tested?
Added a new test suite `ArrowConvertersSuite` that will run tests on conversion of Datasets to Arrow payloads for supported types.  The suite will generate a Dataset and matching Arrow JSON data, then the dataset is converted to an Arrow payload and finally validated against the JSON data.  This will ensure that the schema and data has been converted correctly.

Added PySpark tests to verify the `toPandas` method is producing equal DataFrames with and without pyarrow.  A roundtrip test to ensure the pandas DataFrame produced by pyspark is equal to a one made directly with pandas.

Author: Bryan Cutler <cu...@gmail.com>
Author: Li Jin <ic...@gmail.com>
Author: Li Jin <li...@twosigma.com>
Author: Wes McKinney <we...@twosigma.com>

Closes #18459 from BryanCutler/toPandas_with_arrow-SPARK-13534.


Project: http://git-wip-us.apache.org/repos/asf/spark/repo
Commit: http://git-wip-us.apache.org/repos/asf/spark/commit/d03aebbe
Tree: http://git-wip-us.apache.org/repos/asf/spark/tree/d03aebbe
Diff: http://git-wip-us.apache.org/repos/asf/spark/diff/d03aebbe

Branch: refs/heads/master
Commit: d03aebbe6508ba441dc87f9546f27aeb27553d77
Parents: 2bfd5ac
Author: Bryan Cutler <cu...@gmail.com>
Authored: Mon Jul 10 15:21:03 2017 -0700
Committer: Holden Karau <ho...@us.ibm.com>
Committed: Mon Jul 10 15:21:03 2017 -0700

----------------------------------------------------------------------
 bin/pyspark                                     |    2 +-
 dev/deps/spark-deps-hadoop-2.6                  |    5 +
 dev/deps/spark-deps-hadoop-2.7                  |    5 +
 pom.xml                                         |   20 +
 python/pyspark/serializers.py                   |   17 +
 python/pyspark/sql/dataframe.py                 |   48 +-
 python/pyspark/sql/tests.py                     |   78 +-
 .../org/apache/spark/sql/internal/SQLConf.scala |   22 +
 sql/core/pom.xml                                |    4 +
 .../scala/org/apache/spark/sql/Dataset.scala    |   20 +
 .../sql/execution/arrow/ArrowConverters.scala   |  429 ++++++
 .../execution/arrow/ArrowConvertersSuite.scala  | 1222 ++++++++++++++++++
 12 files changed, 1859 insertions(+), 13 deletions(-)
----------------------------------------------------------------------


http://git-wip-us.apache.org/repos/asf/spark/blob/d03aebbe/bin/pyspark
----------------------------------------------------------------------
diff --git a/bin/pyspark b/bin/pyspark
index d3b512e..dd28627 100755
--- a/bin/pyspark
+++ b/bin/pyspark
@@ -68,7 +68,7 @@ if [[ -n "$SPARK_TESTING" ]]; then
   unset YARN_CONF_DIR
   unset HADOOP_CONF_DIR
   export PYTHONHASHSEED=0
-  exec "$PYSPARK_DRIVER_PYTHON" -m "$1"
+  exec "$PYSPARK_DRIVER_PYTHON" -m "$@"
   exit
 fi
 

http://git-wip-us.apache.org/repos/asf/spark/blob/d03aebbe/dev/deps/spark-deps-hadoop-2.6
----------------------------------------------------------------------
diff --git a/dev/deps/spark-deps-hadoop-2.6 b/dev/deps/spark-deps-hadoop-2.6
index c132531..1a6515b 100644
--- a/dev/deps/spark-deps-hadoop-2.6
+++ b/dev/deps/spark-deps-hadoop-2.6
@@ -13,6 +13,9 @@ apacheds-kerberos-codec-2.0.0-M15.jar
 api-asn1-api-1.0.0-M20.jar
 api-util-1.0.0-M20.jar
 arpack_combined_all-0.1.jar
+arrow-format-0.4.0.jar
+arrow-memory-0.4.0.jar
+arrow-vector-0.4.0.jar
 avro-1.7.7.jar
 avro-ipc-1.7.7.jar
 avro-mapred-1.7.7-hadoop2.jar
@@ -55,6 +58,7 @@ datanucleus-core-3.2.10.jar
 datanucleus-rdbms-3.2.9.jar
 derby-10.12.1.1.jar
 eigenbase-properties-1.1.5.jar
+flatbuffers-1.2.0-3f79e055.jar
 gson-2.2.4.jar
 guava-14.0.1.jar
 guice-3.0.jar
@@ -77,6 +81,7 @@ hadoop-yarn-server-web-proxy-2.6.5.jar
 hk2-api-2.4.0-b34.jar
 hk2-locator-2.4.0-b34.jar
 hk2-utils-2.4.0-b34.jar
+hppc-0.7.1.jar
 htrace-core-3.0.4.jar
 httpclient-4.5.2.jar
 httpcore-4.4.4.jar

http://git-wip-us.apache.org/repos/asf/spark/blob/d03aebbe/dev/deps/spark-deps-hadoop-2.7
----------------------------------------------------------------------
diff --git a/dev/deps/spark-deps-hadoop-2.7 b/dev/deps/spark-deps-hadoop-2.7
index ac5abd2..09e5a42 100644
--- a/dev/deps/spark-deps-hadoop-2.7
+++ b/dev/deps/spark-deps-hadoop-2.7
@@ -13,6 +13,9 @@ apacheds-kerberos-codec-2.0.0-M15.jar
 api-asn1-api-1.0.0-M20.jar
 api-util-1.0.0-M20.jar
 arpack_combined_all-0.1.jar
+arrow-format-0.4.0.jar
+arrow-memory-0.4.0.jar
+arrow-vector-0.4.0.jar
 avro-1.7.7.jar
 avro-ipc-1.7.7.jar
 avro-mapred-1.7.7-hadoop2.jar
@@ -55,6 +58,7 @@ datanucleus-core-3.2.10.jar
 datanucleus-rdbms-3.2.9.jar
 derby-10.12.1.1.jar
 eigenbase-properties-1.1.5.jar
+flatbuffers-1.2.0-3f79e055.jar
 gson-2.2.4.jar
 guava-14.0.1.jar
 guice-3.0.jar
@@ -77,6 +81,7 @@ hadoop-yarn-server-web-proxy-2.7.3.jar
 hk2-api-2.4.0-b34.jar
 hk2-locator-2.4.0-b34.jar
 hk2-utils-2.4.0-b34.jar
+hppc-0.7.1.jar
 htrace-core-3.1.0-incubating.jar
 httpclient-4.5.2.jar
 httpcore-4.4.4.jar

http://git-wip-us.apache.org/repos/asf/spark/blob/d03aebbe/pom.xml
----------------------------------------------------------------------
diff --git a/pom.xml b/pom.xml
index 5f52407..f124ba4 100644
--- a/pom.xml
+++ b/pom.xml
@@ -181,6 +181,7 @@
     <paranamer.version>2.6</paranamer.version>
     <maven-antrun.version>1.8</maven-antrun.version>
     <commons-crypto.version>1.0.0</commons-crypto.version>
+    <arrow.version>0.4.0</arrow.version>
 
     <test.java.home>${java.home}</test.java.home>
     <test.exclude.tags></test.exclude.tags>
@@ -1878,6 +1879,25 @@
         <artifactId>paranamer</artifactId>
         <version>${paranamer.version}</version>
       </dependency>
+      <dependency>
+        <groupId>org.apache.arrow</groupId>
+        <artifactId>arrow-vector</artifactId>
+        <version>${arrow.version}</version>
+        <exclusions>
+          <exclusion>
+            <groupId>com.fasterxml.jackson.core</groupId>
+            <artifactId>jackson-annotations</artifactId>
+          </exclusion>
+          <exclusion>
+            <groupId>com.fasterxml.jackson.core</groupId>
+            <artifactId>jackson-databind</artifactId>
+          </exclusion>
+          <exclusion>
+            <groupId>io.netty</groupId>
+            <artifactId>netty-handler</artifactId>
+          </exclusion>
+        </exclusions>
+      </dependency>
     </dependencies>
   </dependencyManagement>
 

http://git-wip-us.apache.org/repos/asf/spark/blob/d03aebbe/python/pyspark/serializers.py
----------------------------------------------------------------------
diff --git a/python/pyspark/serializers.py b/python/pyspark/serializers.py
index ea5e00e..d5c2a75 100644
--- a/python/pyspark/serializers.py
+++ b/python/pyspark/serializers.py
@@ -182,6 +182,23 @@ class FramedSerializer(Serializer):
         raise NotImplementedError
 
 
+class ArrowSerializer(FramedSerializer):
+    """
+    Serializes an Arrow stream.
+    """
+
+    def dumps(self, obj):
+        raise NotImplementedError
+
+    def loads(self, obj):
+        import pyarrow as pa
+        reader = pa.RecordBatchFileReader(pa.BufferReader(obj))
+        return reader.read_all()
+
+    def __repr__(self):
+        return "ArrowSerializer"
+
+
 class BatchedSerializer(Serializer):
 
     """

http://git-wip-us.apache.org/repos/asf/spark/blob/d03aebbe/python/pyspark/sql/dataframe.py
----------------------------------------------------------------------
diff --git a/python/pyspark/sql/dataframe.py b/python/pyspark/sql/dataframe.py
index 27a6dad..944739b 100644
--- a/python/pyspark/sql/dataframe.py
+++ b/python/pyspark/sql/dataframe.py
@@ -29,7 +29,8 @@ import warnings
 
 from pyspark import copy_func, since
 from pyspark.rdd import RDD, _load_from_socket, ignore_unicode_prefix
-from pyspark.serializers import BatchedSerializer, PickleSerializer, UTF8Deserializer
+from pyspark.serializers import ArrowSerializer, BatchedSerializer, PickleSerializer, \
+    UTF8Deserializer
 from pyspark.storagelevel import StorageLevel
 from pyspark.traceback_utils import SCCallSiteSync
 from pyspark.sql.types import _parse_datatype_json_string
@@ -1710,7 +1711,8 @@ class DataFrame(object):
 
     @since(1.3)
     def toPandas(self):
-        """Returns the contents of this :class:`DataFrame` as Pandas ``pandas.DataFrame``.
+        """
+        Returns the contents of this :class:`DataFrame` as Pandas ``pandas.DataFrame``.
 
         This is only available if Pandas is installed and available.
 
@@ -1723,18 +1725,42 @@ class DataFrame(object):
         1    5    Bob
         """
         import pandas as pd
+        if self.sql_ctx.getConf("spark.sql.execution.arrow.enable", "false").lower() == "true":
+            try:
+                import pyarrow
+                tables = self._collectAsArrow()
+                if tables:
+                    table = pyarrow.concat_tables(tables)
+                    return table.to_pandas()
+                else:
+                    return pd.DataFrame.from_records([], columns=self.columns)
+            except ImportError as e:
+                msg = "note: pyarrow must be installed and available on calling Python process " \
+                      "if using spark.sql.execution.arrow.enable=true"
+                raise ImportError("%s\n%s" % (e.message, msg))
+        else:
+            dtype = {}
+            for field in self.schema:
+                pandas_type = _to_corrected_pandas_type(field.dataType)
+                if pandas_type is not None:
+                    dtype[field.name] = pandas_type
 
-        dtype = {}
-        for field in self.schema:
-            pandas_type = _to_corrected_pandas_type(field.dataType)
-            if pandas_type is not None:
-                dtype[field.name] = pandas_type
+            pdf = pd.DataFrame.from_records(self.collect(), columns=self.columns)
 
-        pdf = pd.DataFrame.from_records(self.collect(), columns=self.columns)
+            for f, t in dtype.items():
+                pdf[f] = pdf[f].astype(t, copy=False)
+            return pdf
 
-        for f, t in dtype.items():
-            pdf[f] = pdf[f].astype(t, copy=False)
-        return pdf
+    def _collectAsArrow(self):
+        """
+        Returns all records as list of deserialized ArrowPayloads, pyarrow must be installed
+        and available.
+
+        .. note:: Experimental.
+        """
+        with SCCallSiteSync(self._sc) as css:
+            port = self._jdf.collectAsArrowToPython()
+        return list(_load_from_socket(port, ArrowSerializer()))
 
     ##########################################################################################
     # Pandas compatibility

http://git-wip-us.apache.org/repos/asf/spark/blob/d03aebbe/python/pyspark/sql/tests.py
----------------------------------------------------------------------
diff --git a/python/pyspark/sql/tests.py b/python/pyspark/sql/tests.py
index 9db2f40..bd8477e 100644
--- a/python/pyspark/sql/tests.py
+++ b/python/pyspark/sql/tests.py
@@ -58,12 +58,21 @@ from pyspark import SparkContext
 from pyspark.sql import SparkSession, SQLContext, HiveContext, Column, Row
 from pyspark.sql.types import *
 from pyspark.sql.types import UserDefinedType, _infer_type, _make_type_verifier
-from pyspark.tests import ReusedPySparkTestCase, SparkSubmitTests
+from pyspark.tests import QuietTest, ReusedPySparkTestCase, SparkSubmitTests
 from pyspark.sql.functions import UserDefinedFunction, sha2, lit
 from pyspark.sql.window import Window
 from pyspark.sql.utils import AnalysisException, ParseException, IllegalArgumentException
 
 
+_have_arrow = False
+try:
+    import pyarrow
+    _have_arrow = True
+except:
+    # No Arrow, but that's okay, we'll skip those tests
+    pass
+
+
 class UTCOffsetTimezone(datetime.tzinfo):
     """
     Specifies timezone in UTC offset
@@ -2843,6 +2852,73 @@ class DataTypeVerificationTests(unittest.TestCase):
                 _make_type_verifier(data_type, nullable=False)(obj)
 
 
+@unittest.skipIf(not _have_arrow, "Arrow not installed")
+class ArrowTests(ReusedPySparkTestCase):
+
+    @classmethod
+    def setUpClass(cls):
+        ReusedPySparkTestCase.setUpClass()
+        cls.spark = SparkSession(cls.sc)
+        cls.spark.conf.set("spark.sql.execution.arrow.enable", "true")
+        cls.schema = StructType([
+            StructField("1_str_t", StringType(), True),
+            StructField("2_int_t", IntegerType(), True),
+            StructField("3_long_t", LongType(), True),
+            StructField("4_float_t", FloatType(), True),
+            StructField("5_double_t", DoubleType(), True)])
+        cls.data = [("a", 1, 10, 0.2, 2.0),
+                    ("b", 2, 20, 0.4, 4.0),
+                    ("c", 3, 30, 0.8, 6.0)]
+
+    def assertFramesEqual(self, df_with_arrow, df_without):
+        msg = ("DataFrame from Arrow is not equal" +
+               ("\n\nWith Arrow:\n%s\n%s" % (df_with_arrow, df_with_arrow.dtypes)) +
+               ("\n\nWithout:\n%s\n%s" % (df_without, df_without.dtypes)))
+        self.assertTrue(df_without.equals(df_with_arrow), msg=msg)
+
+    def test_unsupported_datatype(self):
+        schema = StructType([StructField("array", ArrayType(IntegerType(), False), True)])
+        df = self.spark.createDataFrame([([1, 2, 3],)], schema=schema)
+        with QuietTest(self.sc):
+            self.assertRaises(Exception, lambda: df.toPandas())
+
+    def test_null_conversion(self):
+        df_null = self.spark.createDataFrame([tuple([None for _ in range(len(self.data[0]))])] +
+                                             self.data)
+        pdf = df_null.toPandas()
+        null_counts = pdf.isnull().sum().tolist()
+        self.assertTrue(all([c == 1 for c in null_counts]))
+
+    def test_toPandas_arrow_toggle(self):
+        df = self.spark.createDataFrame(self.data, schema=self.schema)
+        self.spark.conf.set("spark.sql.execution.arrow.enable", "false")
+        pdf = df.toPandas()
+        self.spark.conf.set("spark.sql.execution.arrow.enable", "true")
+        pdf_arrow = df.toPandas()
+        self.assertFramesEqual(pdf_arrow, pdf)
+
+    def test_pandas_round_trip(self):
+        import pandas as pd
+        import numpy as np
+        data_dict = {}
+        for j, name in enumerate(self.schema.names):
+            data_dict[name] = [self.data[i][j] for i in range(len(self.data))]
+        # need to convert these to numpy types first
+        data_dict["2_int_t"] = np.int32(data_dict["2_int_t"])
+        data_dict["4_float_t"] = np.float32(data_dict["4_float_t"])
+        pdf = pd.DataFrame(data=data_dict)
+        df = self.spark.createDataFrame(self.data, schema=self.schema)
+        pdf_arrow = df.toPandas()
+        self.assertFramesEqual(pdf_arrow, pdf)
+
+    def test_filtered_frame(self):
+        df = self.spark.range(3).toDF("i")
+        pdf = df.filter("i < 0").toPandas()
+        self.assertEqual(len(pdf.columns), 1)
+        self.assertEqual(pdf.columns[0], "i")
+        self.assertTrue(pdf.empty)
+
+
 if __name__ == "__main__":
     from pyspark.sql.tests import *
     if xmlrunner:

http://git-wip-us.apache.org/repos/asf/spark/blob/d03aebbe/sql/catalyst/src/main/scala/org/apache/spark/sql/internal/SQLConf.scala
----------------------------------------------------------------------
diff --git a/sql/catalyst/src/main/scala/org/apache/spark/sql/internal/SQLConf.scala b/sql/catalyst/src/main/scala/org/apache/spark/sql/internal/SQLConf.scala
index 25152f3..643587a 100644
--- a/sql/catalyst/src/main/scala/org/apache/spark/sql/internal/SQLConf.scala
+++ b/sql/catalyst/src/main/scala/org/apache/spark/sql/internal/SQLConf.scala
@@ -855,6 +855,24 @@ object SQLConf {
       .intConf
       .createWithDefault(UnsafeExternalSorter.DEFAULT_NUM_ELEMENTS_FOR_SPILL_THRESHOLD.toInt)
 
+  val ARROW_EXECUTION_ENABLE =
+    buildConf("spark.sql.execution.arrow.enable")
+      .internal()
+      .doc("Make use of Apache Arrow for columnar data transfers. Currently available " +
+        "for use with pyspark.sql.DataFrame.toPandas with the following data types: " +
+        "StringType, BinaryType, BooleanType, DoubleType, FloatType, ByteType, IntegerType, " +
+        "LongType, ShortType")
+      .booleanConf
+      .createWithDefault(false)
+
+  val ARROW_EXECUTION_MAX_RECORDS_PER_BATCH =
+    buildConf("spark.sql.execution.arrow.maxRecordsPerBatch")
+      .internal()
+      .doc("When using Apache Arrow, limit the maximum number of records that can be written " +
+        "to a single ArrowRecordBatch in memory. If set to zero or negative there is no limit.")
+      .intConf
+      .createWithDefault(10000)
+
   object Deprecated {
     val MAPRED_REDUCE_TASKS = "mapred.reduce.tasks"
   }
@@ -1115,6 +1133,10 @@ class SQLConf extends Serializable with Logging {
 
   def starSchemaFTRatio: Double = getConf(STARSCHEMA_FACT_TABLE_RATIO)
 
+  def arrowEnable: Boolean = getConf(ARROW_EXECUTION_ENABLE)
+
+  def arrowMaxRecordsPerBatch: Int = getConf(ARROW_EXECUTION_MAX_RECORDS_PER_BATCH)
+
   /** ********************** SQLConf functionality methods ************ */
 
   /** Set Spark SQL configuration properties. */

http://git-wip-us.apache.org/repos/asf/spark/blob/d03aebbe/sql/core/pom.xml
----------------------------------------------------------------------
diff --git a/sql/core/pom.xml b/sql/core/pom.xml
index 1bc34a6..661c31d 100644
--- a/sql/core/pom.xml
+++ b/sql/core/pom.xml
@@ -104,6 +104,10 @@
       <version>${fasterxml.jackson.version}</version>
     </dependency>
     <dependency>
+      <groupId>org.apache.arrow</groupId>
+      <artifactId>arrow-vector</artifactId>
+    </dependency>
+    <dependency>
       <groupId>org.apache.xbean</groupId>
       <artifactId>xbean-asm5-shaded</artifactId>
     </dependency>

http://git-wip-us.apache.org/repos/asf/spark/blob/d03aebbe/sql/core/src/main/scala/org/apache/spark/sql/Dataset.scala
----------------------------------------------------------------------
diff --git a/sql/core/src/main/scala/org/apache/spark/sql/Dataset.scala b/sql/core/src/main/scala/org/apache/spark/sql/Dataset.scala
index dfb5119..a777383 100644
--- a/sql/core/src/main/scala/org/apache/spark/sql/Dataset.scala
+++ b/sql/core/src/main/scala/org/apache/spark/sql/Dataset.scala
@@ -46,6 +46,7 @@ import org.apache.spark.sql.catalyst.plans.logical._
 import org.apache.spark.sql.catalyst.plans.physical.{Partitioning, PartitioningCollection}
 import org.apache.spark.sql.catalyst.util.DateTimeUtils
 import org.apache.spark.sql.execution._
+import org.apache.spark.sql.execution.arrow.{ArrowConverters, ArrowPayload}
 import org.apache.spark.sql.execution.command._
 import org.apache.spark.sql.execution.datasources.LogicalRelation
 import org.apache.spark.sql.execution.python.EvaluatePython
@@ -2907,6 +2908,16 @@ class Dataset[T] private[sql](
     }
   }
 
+  /**
+   * Collect a Dataset as ArrowPayload byte arrays and serve to PySpark.
+   */
+  private[sql] def collectAsArrowToPython(): Int = {
+    withNewExecutionId {
+      val iter = toArrowPayload.collect().iterator.map(_.asPythonSerializable)
+      PythonRDD.serveIterator(iter, "serve-Arrow")
+    }
+  }
+
   private[sql] def toPythonIterator(): Int = {
     withNewExecutionId {
       PythonRDD.toLocalIteratorAndServe(javaToPython.rdd)
@@ -2988,4 +2999,13 @@ class Dataset[T] private[sql](
       Dataset(sparkSession, logicalPlan)
     }
   }
+
+  /** Convert to an RDD of ArrowPayload byte arrays */
+  private[sql] def toArrowPayload: RDD[ArrowPayload] = {
+    val schemaCaptured = this.schema
+    val maxRecordsPerBatch = sparkSession.sessionState.conf.arrowMaxRecordsPerBatch
+    queryExecution.toRdd.mapPartitionsInternal { iter =>
+      ArrowConverters.toPayloadIterator(iter, schemaCaptured, maxRecordsPerBatch)
+    }
+  }
 }

http://git-wip-us.apache.org/repos/asf/spark/blob/d03aebbe/sql/core/src/main/scala/org/apache/spark/sql/execution/arrow/ArrowConverters.scala
----------------------------------------------------------------------
diff --git a/sql/core/src/main/scala/org/apache/spark/sql/execution/arrow/ArrowConverters.scala b/sql/core/src/main/scala/org/apache/spark/sql/execution/arrow/ArrowConverters.scala
new file mode 100644
index 0000000..6af5c73
--- /dev/null
+++ b/sql/core/src/main/scala/org/apache/spark/sql/execution/arrow/ArrowConverters.scala
@@ -0,0 +1,429 @@
+/*
+* Licensed to the Apache Software Foundation (ASF) under one or more
+* contributor license agreements.  See the NOTICE file distributed with
+* this work for additional information regarding copyright ownership.
+* The ASF licenses this file to You under the Apache License, Version 2.0
+* (the "License"); you may not use this file except in compliance with
+* the License.  You may obtain a copy of the License at
+*
+*    http://www.apache.org/licenses/LICENSE-2.0
+*
+* Unless required by applicable law or agreed to in writing, software
+* distributed under the License is distributed on an "AS IS" BASIS,
+* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+* See the License for the specific language governing permissions and
+* limitations under the License.
+*/
+
+package org.apache.spark.sql.execution.arrow
+
+import java.io.ByteArrayOutputStream
+import java.nio.channels.Channels
+
+import scala.collection.JavaConverters._
+
+import io.netty.buffer.ArrowBuf
+import org.apache.arrow.memory.{BufferAllocator, RootAllocator}
+import org.apache.arrow.vector._
+import org.apache.arrow.vector.BaseValueVector.BaseMutator
+import org.apache.arrow.vector.file._
+import org.apache.arrow.vector.schema.{ArrowFieldNode, ArrowRecordBatch}
+import org.apache.arrow.vector.types.FloatingPointPrecision
+import org.apache.arrow.vector.types.pojo.{ArrowType, Field, FieldType, Schema}
+import org.apache.arrow.vector.util.ByteArrayReadableSeekableByteChannel
+
+import org.apache.spark.sql.catalyst.InternalRow
+import org.apache.spark.sql.types._
+import org.apache.spark.util.Utils
+
+
+/**
+ * Store Arrow data in a form that can be serialized by Spark and served to a Python process.
+ */
+private[sql] class ArrowPayload private[arrow] (payload: Array[Byte]) extends Serializable {
+
+  /**
+   * Convert the ArrowPayload to an ArrowRecordBatch.
+   */
+  def loadBatch(allocator: BufferAllocator): ArrowRecordBatch = {
+    ArrowConverters.byteArrayToBatch(payload, allocator)
+  }
+
+  /**
+   * Get the ArrowPayload as a type that can be served to Python.
+   */
+  def asPythonSerializable: Array[Byte] = payload
+}
+
+private[sql] object ArrowPayload {
+
+  /**
+   * Create an ArrowPayload from an ArrowRecordBatch and Spark schema.
+   */
+  def apply(
+      batch: ArrowRecordBatch,
+      schema: StructType,
+      allocator: BufferAllocator): ArrowPayload = {
+    new ArrowPayload(ArrowConverters.batchToByteArray(batch, schema, allocator))
+  }
+}
+
+private[sql] object ArrowConverters {
+
+  /**
+   * Map a Spark DataType to ArrowType.
+   */
+  private[arrow] def sparkTypeToArrowType(dataType: DataType): ArrowType = {
+    dataType match {
+      case BooleanType => ArrowType.Bool.INSTANCE
+      case ShortType => new ArrowType.Int(8 * ShortType.defaultSize, true)
+      case IntegerType => new ArrowType.Int(8 * IntegerType.defaultSize, true)
+      case LongType => new ArrowType.Int(8 * LongType.defaultSize, true)
+      case FloatType => new ArrowType.FloatingPoint(FloatingPointPrecision.SINGLE)
+      case DoubleType => new ArrowType.FloatingPoint(FloatingPointPrecision.DOUBLE)
+      case ByteType => new ArrowType.Int(8, true)
+      case StringType => ArrowType.Utf8.INSTANCE
+      case BinaryType => ArrowType.Binary.INSTANCE
+      case _ => throw new UnsupportedOperationException(s"Unsupported data type: $dataType")
+    }
+  }
+
+  /**
+   * Convert a Spark Dataset schema to Arrow schema.
+   */
+  private[arrow] def schemaToArrowSchema(schema: StructType): Schema = {
+    val arrowFields = schema.fields.map { f =>
+      new Field(f.name, f.nullable, sparkTypeToArrowType(f.dataType), List.empty[Field].asJava)
+    }
+    new Schema(arrowFields.toList.asJava)
+  }
+
+  /**
+   * Maps Iterator from InternalRow to ArrowPayload. Limit ArrowRecordBatch size in ArrowPayload
+   * by setting maxRecordsPerBatch or use 0 to fully consume rowIter.
+   */
+  private[sql] def toPayloadIterator(
+      rowIter: Iterator[InternalRow],
+      schema: StructType,
+      maxRecordsPerBatch: Int): Iterator[ArrowPayload] = {
+    new Iterator[ArrowPayload] {
+      private val _allocator = new RootAllocator(Long.MaxValue)
+      private var _nextPayload = if (rowIter.nonEmpty) convert() else null
+
+      override def hasNext: Boolean = _nextPayload != null
+
+      override def next(): ArrowPayload = {
+        val obj = _nextPayload
+        if (hasNext) {
+          if (rowIter.hasNext) {
+            _nextPayload = convert()
+          } else {
+            _allocator.close()
+            _nextPayload = null
+          }
+        }
+        obj
+      }
+
+      private def convert(): ArrowPayload = {
+        val batch = internalRowIterToArrowBatch(rowIter, schema, _allocator, maxRecordsPerBatch)
+        ArrowPayload(batch, schema, _allocator)
+      }
+    }
+  }
+
+  /**
+   * Iterate over InternalRows and write to an ArrowRecordBatch, stopping when rowIter is consumed
+   * or the number of records in the batch equals maxRecordsInBatch.  If maxRecordsPerBatch is 0,
+   * then rowIter will be fully consumed.
+   */
+  private def internalRowIterToArrowBatch(
+      rowIter: Iterator[InternalRow],
+      schema: StructType,
+      allocator: BufferAllocator,
+      maxRecordsPerBatch: Int = 0): ArrowRecordBatch = {
+
+    val columnWriters = schema.fields.zipWithIndex.map { case (field, ordinal) =>
+      ColumnWriter(field.dataType, ordinal, allocator).init()
+    }
+
+    val writerLength = columnWriters.length
+    var recordsInBatch = 0
+    while (rowIter.hasNext && (maxRecordsPerBatch <= 0 || recordsInBatch < maxRecordsPerBatch)) {
+      val row = rowIter.next()
+      var i = 0
+      while (i < writerLength) {
+        columnWriters(i).write(row)
+        i += 1
+      }
+      recordsInBatch += 1
+    }
+
+    val (fieldNodes, bufferArrays) = columnWriters.map(_.finish()).unzip
+    val buffers = bufferArrays.flatten
+
+    val rowLength = if (fieldNodes.nonEmpty) fieldNodes.head.getLength else 0
+    val recordBatch = new ArrowRecordBatch(rowLength,
+      fieldNodes.toList.asJava, buffers.toList.asJava)
+
+    buffers.foreach(_.release())
+    recordBatch
+  }
+
+  /**
+   * Convert an ArrowRecordBatch to a byte array and close batch to release resources. Once closed,
+   * the batch can no longer be used.
+   */
+  private[arrow] def batchToByteArray(
+      batch: ArrowRecordBatch,
+      schema: StructType,
+      allocator: BufferAllocator): Array[Byte] = {
+    val arrowSchema = ArrowConverters.schemaToArrowSchema(schema)
+    val root = VectorSchemaRoot.create(arrowSchema, allocator)
+    val out = new ByteArrayOutputStream()
+    val writer = new ArrowFileWriter(root, null, Channels.newChannel(out))
+
+    // Write a batch to byte stream, ensure the batch, allocator and writer are closed
+    Utils.tryWithSafeFinally {
+      val loader = new VectorLoader(root)
+      loader.load(batch)
+      writer.writeBatch()  // writeBatch can throw IOException
+    } {
+      batch.close()
+      root.close()
+      writer.close()
+    }
+    out.toByteArray
+  }
+
+  /**
+   * Convert a byte array to an ArrowRecordBatch.
+   */
+  private[arrow] def byteArrayToBatch(
+      batchBytes: Array[Byte],
+      allocator: BufferAllocator): ArrowRecordBatch = {
+    val in = new ByteArrayReadableSeekableByteChannel(batchBytes)
+    val reader = new ArrowFileReader(in, allocator)
+
+    // Read a batch from a byte stream, ensure the reader is closed
+    Utils.tryWithSafeFinally {
+      val root = reader.getVectorSchemaRoot  // throws IOException
+      val unloader = new VectorUnloader(root)
+      reader.loadNextBatch()  // throws IOException
+      unloader.getRecordBatch
+    } {
+      reader.close()
+    }
+  }
+}
+
+/**
+ * Interface for writing InternalRows to Arrow Buffers.
+ */
+private[arrow] trait ColumnWriter {
+  def init(): this.type
+  def write(row: InternalRow): Unit
+
+  /**
+   * Clear the column writer and return the ArrowFieldNode and ArrowBuf.
+   * This should be called only once after all the data is written.
+   */
+  def finish(): (ArrowFieldNode, Array[ArrowBuf])
+}
+
+/**
+ * Base class for flat arrow column writer, i.e., column without children.
+ */
+private[arrow] abstract class PrimitiveColumnWriter(val ordinal: Int)
+  extends ColumnWriter {
+
+  def getFieldType(dtype: ArrowType): FieldType = FieldType.nullable(dtype)
+
+  def valueVector: BaseDataValueVector
+  def valueMutator: BaseMutator
+
+  def setNull(): Unit
+  def setValue(row: InternalRow): Unit
+
+  protected var count = 0
+  protected var nullCount = 0
+
+  override def init(): this.type = {
+    valueVector.allocateNew()
+    this
+  }
+
+  override def write(row: InternalRow): Unit = {
+    if (row.isNullAt(ordinal)) {
+      setNull()
+      nullCount += 1
+    } else {
+      setValue(row)
+    }
+    count += 1
+  }
+
+  override def finish(): (ArrowFieldNode, Array[ArrowBuf]) = {
+    valueMutator.setValueCount(count)
+    val fieldNode = new ArrowFieldNode(count, nullCount)
+    val valueBuffers = valueVector.getBuffers(true)
+    (fieldNode, valueBuffers)
+  }
+}
+
+private[arrow] class BooleanColumnWriter(dtype: ArrowType, ordinal: Int, allocator: BufferAllocator)
+  extends PrimitiveColumnWriter(ordinal) {
+  override val valueVector: NullableBitVector
+    = new NullableBitVector("BooleanValue", getFieldType(dtype), allocator)
+  override val valueMutator: NullableBitVector#Mutator = valueVector.getMutator
+
+  override def setNull(): Unit = valueMutator.setNull(count)
+  override def setValue(row: InternalRow): Unit
+    = valueMutator.setSafe(count, if (row.getBoolean(ordinal)) 1 else 0 )
+}
+
+private[arrow] class ShortColumnWriter(dtype: ArrowType, ordinal: Int, allocator: BufferAllocator)
+  extends PrimitiveColumnWriter(ordinal) {
+  override val valueVector: NullableSmallIntVector
+    = new NullableSmallIntVector("ShortValue", getFieldType(dtype: ArrowType), allocator)
+  override val valueMutator: NullableSmallIntVector#Mutator = valueVector.getMutator
+
+  override def setNull(): Unit = valueMutator.setNull(count)
+  override def setValue(row: InternalRow): Unit
+    = valueMutator.setSafe(count, row.getShort(ordinal))
+}
+
+private[arrow] class IntegerColumnWriter(dtype: ArrowType, ordinal: Int, allocator: BufferAllocator)
+  extends PrimitiveColumnWriter(ordinal) {
+  override val valueVector: NullableIntVector
+    = new NullableIntVector("IntValue", getFieldType(dtype), allocator)
+  override val valueMutator: NullableIntVector#Mutator = valueVector.getMutator
+
+  override def setNull(): Unit = valueMutator.setNull(count)
+  override def setValue(row: InternalRow): Unit
+    = valueMutator.setSafe(count, row.getInt(ordinal))
+}
+
+private[arrow] class LongColumnWriter(dtype: ArrowType, ordinal: Int, allocator: BufferAllocator)
+  extends PrimitiveColumnWriter(ordinal) {
+  override val valueVector: NullableBigIntVector
+    = new NullableBigIntVector("LongValue", getFieldType(dtype), allocator)
+  override val valueMutator: NullableBigIntVector#Mutator = valueVector.getMutator
+
+  override def setNull(): Unit = valueMutator.setNull(count)
+  override def setValue(row: InternalRow): Unit
+    = valueMutator.setSafe(count, row.getLong(ordinal))
+}
+
+private[arrow] class FloatColumnWriter(dtype: ArrowType, ordinal: Int, allocator: BufferAllocator)
+  extends PrimitiveColumnWriter(ordinal) {
+  override val valueVector: NullableFloat4Vector
+    = new NullableFloat4Vector("FloatValue", getFieldType(dtype), allocator)
+  override val valueMutator: NullableFloat4Vector#Mutator = valueVector.getMutator
+
+  override def setNull(): Unit = valueMutator.setNull(count)
+  override def setValue(row: InternalRow): Unit
+    = valueMutator.setSafe(count, row.getFloat(ordinal))
+}
+
+private[arrow] class DoubleColumnWriter(dtype: ArrowType, ordinal: Int, allocator: BufferAllocator)
+  extends PrimitiveColumnWriter(ordinal) {
+  override val valueVector: NullableFloat8Vector
+    = new NullableFloat8Vector("DoubleValue", getFieldType(dtype), allocator)
+  override val valueMutator: NullableFloat8Vector#Mutator = valueVector.getMutator
+
+  override def setNull(): Unit = valueMutator.setNull(count)
+  override def setValue(row: InternalRow): Unit
+    = valueMutator.setSafe(count, row.getDouble(ordinal))
+}
+
+private[arrow] class ByteColumnWriter(dtype: ArrowType, ordinal: Int, allocator: BufferAllocator)
+  extends PrimitiveColumnWriter(ordinal) {
+  override val valueVector: NullableUInt1Vector
+    = new NullableUInt1Vector("ByteValue", getFieldType(dtype), allocator)
+  override val valueMutator: NullableUInt1Vector#Mutator = valueVector.getMutator
+
+  override def setNull(): Unit = valueMutator.setNull(count)
+  override def setValue(row: InternalRow): Unit
+    = valueMutator.setSafe(count, row.getByte(ordinal))
+}
+
+private[arrow] class UTF8StringColumnWriter(
+    dtype: ArrowType,
+    ordinal: Int,
+    allocator: BufferAllocator)
+  extends PrimitiveColumnWriter(ordinal) {
+  override val valueVector: NullableVarCharVector
+    = new NullableVarCharVector("UTF8StringValue", getFieldType(dtype), allocator)
+  override val valueMutator: NullableVarCharVector#Mutator = valueVector.getMutator
+
+  override def setNull(): Unit = valueMutator.setNull(count)
+  override def setValue(row: InternalRow): Unit = {
+    val str = row.getUTF8String(ordinal)
+    valueMutator.setSafe(count, str.getByteBuffer, 0, str.numBytes)
+  }
+}
+
+private[arrow] class BinaryColumnWriter(dtype: ArrowType, ordinal: Int, allocator: BufferAllocator)
+  extends PrimitiveColumnWriter(ordinal) {
+  override val valueVector: NullableVarBinaryVector
+    = new NullableVarBinaryVector("BinaryValue", getFieldType(dtype), allocator)
+  override val valueMutator: NullableVarBinaryVector#Mutator = valueVector.getMutator
+
+  override def setNull(): Unit = valueMutator.setNull(count)
+  override def setValue(row: InternalRow): Unit = {
+    val bytes = row.getBinary(ordinal)
+    valueMutator.setSafe(count, bytes, 0, bytes.length)
+  }
+}
+
+private[arrow] class DateColumnWriter(dtype: ArrowType, ordinal: Int, allocator: BufferAllocator)
+  extends PrimitiveColumnWriter(ordinal) {
+  override val valueVector: NullableDateDayVector
+    = new NullableDateDayVector("DateValue", getFieldType(dtype), allocator)
+  override val valueMutator: NullableDateDayVector#Mutator = valueVector.getMutator
+
+  override def setNull(): Unit = valueMutator.setNull(count)
+  override def setValue(row: InternalRow): Unit = {
+    valueMutator.setSafe(count, row.getInt(ordinal))
+  }
+}
+
+private[arrow] class TimeStampColumnWriter(
+    dtype: ArrowType,
+    ordinal: Int,
+    allocator: BufferAllocator)
+  extends PrimitiveColumnWriter(ordinal) {
+  override val valueVector: NullableTimeStampMicroVector
+    = new NullableTimeStampMicroVector("TimeStampValue", getFieldType(dtype), allocator)
+  override val valueMutator: NullableTimeStampMicroVector#Mutator = valueVector.getMutator
+
+  override def setNull(): Unit = valueMutator.setNull(count)
+  override def setValue(row: InternalRow): Unit = {
+    valueMutator.setSafe(count, row.getLong(ordinal))
+  }
+}
+
+private[arrow] object ColumnWriter {
+
+  /**
+   * Create an Arrow ColumnWriter given the type and ordinal of row.
+   */
+  def apply(dataType: DataType, ordinal: Int, allocator: BufferAllocator): ColumnWriter = {
+    val dtype = ArrowConverters.sparkTypeToArrowType(dataType)
+    dataType match {
+      case BooleanType => new BooleanColumnWriter(dtype, ordinal, allocator)
+      case ShortType => new ShortColumnWriter(dtype, ordinal, allocator)
+      case IntegerType => new IntegerColumnWriter(dtype, ordinal, allocator)
+      case LongType => new LongColumnWriter(dtype, ordinal, allocator)
+      case FloatType => new FloatColumnWriter(dtype, ordinal, allocator)
+      case DoubleType => new DoubleColumnWriter(dtype, ordinal, allocator)
+      case ByteType => new ByteColumnWriter(dtype, ordinal, allocator)
+      case StringType => new UTF8StringColumnWriter(dtype, ordinal, allocator)
+      case BinaryType => new BinaryColumnWriter(dtype, ordinal, allocator)
+      case DateType => new DateColumnWriter(dtype, ordinal, allocator)
+      case TimestampType => new TimeStampColumnWriter(dtype, ordinal, allocator)
+      case _ => throw new UnsupportedOperationException(s"Unsupported data type: $dataType")
+    }
+  }
+}

http://git-wip-us.apache.org/repos/asf/spark/blob/d03aebbe/sql/core/src/test/scala/org/apache/spark/sql/execution/arrow/ArrowConvertersSuite.scala
----------------------------------------------------------------------
diff --git a/sql/core/src/test/scala/org/apache/spark/sql/execution/arrow/ArrowConvertersSuite.scala b/sql/core/src/test/scala/org/apache/spark/sql/execution/arrow/ArrowConvertersSuite.scala
new file mode 100644
index 0000000..159328c
--- /dev/null
+++ b/sql/core/src/test/scala/org/apache/spark/sql/execution/arrow/ArrowConvertersSuite.scala
@@ -0,0 +1,1222 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *    http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.apache.spark.sql.execution.arrow
+
+import java.io.File
+import java.nio.charset.StandardCharsets
+import java.sql.{Date, Timestamp}
+import java.text.SimpleDateFormat
+import java.util.Locale
+
+import com.google.common.io.Files
+import org.apache.arrow.memory.RootAllocator
+import org.apache.arrow.vector.{VectorLoader, VectorSchemaRoot}
+import org.apache.arrow.vector.file.json.JsonFileReader
+import org.apache.arrow.vector.util.Validator
+import org.scalatest.BeforeAndAfterAll
+
+import org.apache.spark.SparkException
+import org.apache.spark.sql.{DataFrame, Row}
+import org.apache.spark.sql.test.SharedSQLContext
+import org.apache.spark.sql.types.{BinaryType, StructField, StructType}
+import org.apache.spark.util.Utils
+
+
+class ArrowConvertersSuite extends SharedSQLContext with BeforeAndAfterAll {
+  import testImplicits._
+
+  private var tempDataPath: String = _
+
+  override def beforeAll(): Unit = {
+    super.beforeAll()
+    tempDataPath = Utils.createTempDir(namePrefix = "arrow").getAbsolutePath
+  }
+
+  test("collect to arrow record batch") {
+    val indexData = (1 to 6).toDF("i")
+    val arrowPayloads = indexData.toArrowPayload.collect()
+    assert(arrowPayloads.nonEmpty)
+    assert(arrowPayloads.length == indexData.rdd.getNumPartitions)
+    val allocator = new RootAllocator(Long.MaxValue)
+    val arrowRecordBatches = arrowPayloads.map(_.loadBatch(allocator))
+    val rowCount = arrowRecordBatches.map(_.getLength).sum
+    assert(rowCount === indexData.count())
+    arrowRecordBatches.foreach(batch => assert(batch.getNodes.size() > 0))
+    arrowRecordBatches.foreach(_.close())
+    allocator.close()
+  }
+
+  test("short conversion") {
+    val json =
+      s"""
+         |{
+         |  "schema" : {
+         |    "fields" : [ {
+         |      "name" : "a_s",
+         |      "type" : {
+         |        "name" : "int",
+         |        "isSigned" : true,
+         |        "bitWidth" : 16
+         |      },
+         |      "nullable" : false,
+         |      "children" : [ ],
+         |      "typeLayout" : {
+         |        "vectors" : [ {
+         |          "type" : "VALIDITY",
+         |          "typeBitWidth" : 1
+         |        }, {
+         |          "type" : "DATA",
+         |          "typeBitWidth" : 16
+         |        } ]
+         |      }
+         |    }, {
+         |      "name" : "b_s",
+         |      "type" : {
+         |        "name" : "int",
+         |        "isSigned" : true,
+         |        "bitWidth" : 16
+         |      },
+         |      "nullable" : true,
+         |      "children" : [ ],
+         |      "typeLayout" : {
+         |        "vectors" : [ {
+         |          "type" : "VALIDITY",
+         |          "typeBitWidth" : 1
+         |        }, {
+         |          "type" : "DATA",
+         |          "typeBitWidth" : 16
+         |        } ]
+         |      }
+         |    } ]
+         |  },
+         |  "batches" : [ {
+         |    "count" : 6,
+         |    "columns" : [ {
+         |      "name" : "a_s",
+         |      "count" : 6,
+         |      "VALIDITY" : [ 1, 1, 1, 1, 1, 1 ],
+         |      "DATA" : [ 1, -1, 2, -2, 32767, -32768 ]
+         |    }, {
+         |      "name" : "b_s",
+         |      "count" : 6,
+         |      "VALIDITY" : [ 1, 0, 0, 1, 0, 1 ],
+         |      "DATA" : [ 1, 0, 0, -2, 0, -32768 ]
+         |    } ]
+         |  } ]
+         |}
+       """.stripMargin
+
+    val a_s = List[Short](1, -1, 2, -2, 32767, -32768)
+    val b_s = List[Option[Short]](Some(1), None, None, Some(-2), None, Some(-32768))
+    val df = a_s.zip(b_s).toDF("a_s", "b_s")
+
+    collectAndValidate(df, json, "integer-16bit.json")
+  }
+
+  test("int conversion") {
+    val json =
+      s"""
+         |{
+         |  "schema" : {
+         |    "fields" : [ {
+         |      "name" : "a_i",
+         |      "type" : {
+         |        "name" : "int",
+         |        "isSigned" : true,
+         |        "bitWidth" : 32
+         |      },
+         |      "nullable" : false,
+         |      "children" : [ ],
+         |      "typeLayout" : {
+         |        "vectors" : [ {
+         |          "type" : "VALIDITY",
+         |          "typeBitWidth" : 1
+         |        }, {
+         |          "type" : "DATA",
+         |          "typeBitWidth" : 32
+         |        } ]
+         |      }
+         |    }, {
+         |      "name" : "b_i",
+         |      "type" : {
+         |        "name" : "int",
+         |        "isSigned" : true,
+         |        "bitWidth" : 32
+         |      },
+         |      "nullable" : true,
+         |      "children" : [ ],
+         |      "typeLayout" : {
+         |        "vectors" : [ {
+         |          "type" : "VALIDITY",
+         |          "typeBitWidth" : 1
+         |        }, {
+         |          "type" : "DATA",
+         |          "typeBitWidth" : 32
+         |        } ]
+         |      }
+         |    } ]
+         |  },
+         |  "batches" : [ {
+         |    "count" : 6,
+         |    "columns" : [ {
+         |      "name" : "a_i",
+         |      "count" : 6,
+         |      "VALIDITY" : [ 1, 1, 1, 1, 1, 1 ],
+         |      "DATA" : [ 1, -1, 2, -2, 2147483647, -2147483648 ]
+         |    }, {
+         |      "name" : "b_i",
+         |      "count" : 6,
+         |      "VALIDITY" : [ 1, 0, 0, 1, 0, 1 ],
+         |      "DATA" : [ 1, 0, 0, -2, 0, -2147483648 ]
+         |    } ]
+         |  } ]
+         |}
+       """.stripMargin
+
+    val a_i = List[Int](1, -1, 2, -2, 2147483647, -2147483648)
+    val b_i = List[Option[Int]](Some(1), None, None, Some(-2), None, Some(-2147483648))
+    val df = a_i.zip(b_i).toDF("a_i", "b_i")
+
+    collectAndValidate(df, json, "integer-32bit.json")
+  }
+
+  test("long conversion") {
+    val json =
+      s"""
+         |{
+         |  "schema" : {
+         |    "fields" : [ {
+         |      "name" : "a_l",
+         |      "type" : {
+         |        "name" : "int",
+         |        "isSigned" : true,
+         |        "bitWidth" : 64
+         |      },
+         |      "nullable" : false,
+         |      "children" : [ ],
+         |      "typeLayout" : {
+         |        "vectors" : [ {
+         |          "type" : "VALIDITY",
+         |          "typeBitWidth" : 1
+         |        }, {
+         |          "type" : "DATA",
+         |          "typeBitWidth" : 64
+         |        } ]
+         |      }
+         |    }, {
+         |      "name" : "b_l",
+         |      "type" : {
+         |        "name" : "int",
+         |        "isSigned" : true,
+         |        "bitWidth" : 64
+         |      },
+         |      "nullable" : true,
+         |      "children" : [ ],
+         |      "typeLayout" : {
+         |        "vectors" : [ {
+         |          "type" : "VALIDITY",
+         |          "typeBitWidth" : 1
+         |        }, {
+         |          "type" : "DATA",
+         |          "typeBitWidth" : 64
+         |        } ]
+         |      }
+         |    } ]
+         |  },
+         |  "batches" : [ {
+         |    "count" : 6,
+         |    "columns" : [ {
+         |      "name" : "a_l",
+         |      "count" : 6,
+         |      "VALIDITY" : [ 1, 1, 1, 1, 1, 1 ],
+         |      "DATA" : [ 1, -1, 2, -2, 9223372036854775807, -9223372036854775808 ]
+         |    }, {
+         |      "name" : "b_l",
+         |      "count" : 6,
+         |      "VALIDITY" : [ 1, 0, 0, 1, 0, 1 ],
+         |      "DATA" : [ 1, 0, 0, -2, 0, -9223372036854775808 ]
+         |    } ]
+         |  } ]
+         |}
+       """.stripMargin
+
+    val a_l = List[Long](1, -1, 2, -2, 9223372036854775807L, -9223372036854775808L)
+    val b_l = List[Option[Long]](Some(1), None, None, Some(-2), None, Some(-9223372036854775808L))
+    val df = a_l.zip(b_l).toDF("a_l", "b_l")
+
+    collectAndValidate(df, json, "integer-64bit.json")
+  }
+
+  test("float conversion") {
+    val json =
+      s"""
+         |{
+         |  "schema" : {
+         |    "fields" : [ {
+         |      "name" : "a_f",
+         |      "type" : {
+         |        "name" : "floatingpoint",
+         |        "precision" : "SINGLE"
+         |      },
+         |      "nullable" : false,
+         |      "children" : [ ],
+         |      "typeLayout" : {
+         |        "vectors" : [ {
+         |          "type" : "VALIDITY",
+         |          "typeBitWidth" : 1
+         |        }, {
+         |          "type" : "DATA",
+         |          "typeBitWidth" : 32
+         |        } ]
+         |      }
+         |    }, {
+         |      "name" : "b_f",
+         |      "type" : {
+         |        "name" : "floatingpoint",
+         |        "precision" : "SINGLE"
+         |      },
+         |      "nullable" : true,
+         |      "children" : [ ],
+         |      "typeLayout" : {
+         |        "vectors" : [ {
+         |          "type" : "VALIDITY",
+         |          "typeBitWidth" : 1
+         |        }, {
+         |          "type" : "DATA",
+         |          "typeBitWidth" : 32
+         |        } ]
+         |      }
+         |    } ]
+         |  },
+         |  "batches" : [ {
+         |    "count" : 6,
+         |    "columns" : [ {
+         |      "name" : "a_f",
+         |      "count" : 6,
+         |      "VALIDITY" : [ 1, 1, 1, 1, 1, 1 ],
+         |      "DATA" : [ 1.0, 2.0, 0.01, 200.0, 0.0001, 20000.0 ]
+         |    }, {
+         |      "name" : "b_f",
+         |      "count" : 6,
+         |      "VALIDITY" : [ 1, 0, 0, 1, 0, 1 ],
+         |      "DATA" : [ 1.1, 0.0, 0.0, 2.2, 0.0, 3.3 ]
+         |    } ]
+         |  } ]
+         |}
+       """.stripMargin
+
+    val a_f = List(1.0f, 2.0f, 0.01f, 200.0f, 0.0001f, 20000.0f)
+    val b_f = List[Option[Float]](Some(1.1f), None, None, Some(2.2f), None, Some(3.3f))
+    val df = a_f.zip(b_f).toDF("a_f", "b_f")
+
+    collectAndValidate(df, json, "floating_point-single_precision.json")
+  }
+
+  test("double conversion") {
+    val json =
+      s"""
+         |{
+         |  "schema" : {
+         |    "fields" : [ {
+         |      "name" : "a_d",
+         |      "type" : {
+         |        "name" : "floatingpoint",
+         |        "precision" : "DOUBLE"
+         |      },
+         |      "nullable" : false,
+         |      "children" : [ ],
+         |      "typeLayout" : {
+         |        "vectors" : [ {
+         |          "type" : "VALIDITY",
+         |          "typeBitWidth" : 1
+         |        }, {
+         |          "type" : "DATA",
+         |          "typeBitWidth" : 64
+         |        } ]
+         |      }
+         |    }, {
+         |      "name" : "b_d",
+         |      "type" : {
+         |        "name" : "floatingpoint",
+         |        "precision" : "DOUBLE"
+         |      },
+         |      "nullable" : true,
+         |      "children" : [ ],
+         |      "typeLayout" : {
+         |        "vectors" : [ {
+         |          "type" : "VALIDITY",
+         |          "typeBitWidth" : 1
+         |        }, {
+         |          "type" : "DATA",
+         |          "typeBitWidth" : 64
+         |        } ]
+         |      }
+         |    } ]
+         |  },
+         |  "batches" : [ {
+         |    "count" : 6,
+         |    "columns" : [ {
+         |      "name" : "a_d",
+         |      "count" : 6,
+         |      "VALIDITY" : [ 1, 1, 1, 1, 1, 1 ],
+         |      "DATA" : [ 1.0, 2.0, 0.01, 200.0, 1.0E-4, 20000.0 ]
+         |    }, {
+         |      "name" : "b_d",
+         |      "count" : 6,
+         |      "VALIDITY" : [ 1, 0, 0, 1, 0, 1 ],
+         |      "DATA" : [ 1.1, 0.0, 0.0, 2.2, 0.0, 3.3 ]
+         |    } ]
+         |  } ]
+         |}
+       """.stripMargin
+
+    val a_d = List(1.0, 2.0, 0.01, 200.0, 0.0001, 20000.0)
+    val b_d = List[Option[Double]](Some(1.1), None, None, Some(2.2), None, Some(3.3))
+    val df = a_d.zip(b_d).toDF("a_d", "b_d")
+
+    collectAndValidate(df, json, "floating_point-double_precision.json")
+  }
+
+  test("index conversion") {
+    val data = List[Int](1, 2, 3, 4, 5, 6)
+    val json =
+      s"""
+         |{
+         |  "schema" : {
+         |    "fields" : [ {
+         |      "name" : "i",
+         |      "type" : {
+         |        "name" : "int",
+         |        "isSigned" : true,
+         |        "bitWidth" : 32
+         |      },
+         |      "nullable" : false,
+         |      "children" : [ ],
+         |      "typeLayout" : {
+         |        "vectors" : [ {
+         |          "type" : "VALIDITY",
+         |          "typeBitWidth" : 1
+         |        }, {
+         |          "type" : "DATA",
+         |          "typeBitWidth" : 32
+         |        } ]
+         |      }
+         |    } ]
+         |  },
+         |  "batches" : [ {
+         |    "count" : 6,
+         |    "columns" : [ {
+         |      "name" : "i",
+         |      "count" : 6,
+         |      "VALIDITY" : [ 1, 1, 1, 1, 1, 1 ],
+         |      "DATA" : [ 1, 2, 3, 4, 5, 6 ]
+         |    } ]
+         |  } ]
+         |}
+       """.stripMargin
+    val df = data.toDF("i")
+
+    collectAndValidate(df, json, "indexData-ints.json")
+  }
+
+  test("mixed numeric type conversion") {
+    val json =
+      s"""
+         |{
+         |  "schema" : {
+         |    "fields" : [ {
+         |      "name" : "a",
+         |      "type" : {
+         |        "name" : "int",
+         |        "isSigned" : true,
+         |        "bitWidth" : 16
+         |      },
+         |      "nullable" : false,
+         |      "children" : [ ],
+         |      "typeLayout" : {
+         |        "vectors" : [ {
+         |          "type" : "VALIDITY",
+         |          "typeBitWidth" : 1
+         |        }, {
+         |          "type" : "DATA",
+         |          "typeBitWidth" : 16
+         |        } ]
+         |      }
+         |    }, {
+         |      "name" : "b",
+         |      "type" : {
+         |        "name" : "floatingpoint",
+         |        "precision" : "SINGLE"
+         |      },
+         |      "nullable" : false,
+         |      "children" : [ ],
+         |      "typeLayout" : {
+         |        "vectors" : [ {
+         |          "type" : "VALIDITY",
+         |          "typeBitWidth" : 1
+         |        }, {
+         |          "type" : "DATA",
+         |          "typeBitWidth" : 32
+         |        } ]
+         |      }
+         |    }, {
+         |      "name" : "c",
+         |      "type" : {
+         |        "name" : "int",
+         |        "isSigned" : true,
+         |        "bitWidth" : 32
+         |      },
+         |      "nullable" : false,
+         |      "children" : [ ],
+         |      "typeLayout" : {
+         |        "vectors" : [ {
+         |          "type" : "VALIDITY",
+         |          "typeBitWidth" : 1
+         |        }, {
+         |          "type" : "DATA",
+         |          "typeBitWidth" : 32
+         |        } ]
+         |      }
+         |    }, {
+         |      "name" : "d",
+         |      "type" : {
+         |        "name" : "floatingpoint",
+         |        "precision" : "DOUBLE"
+         |      },
+         |      "nullable" : false,
+         |      "children" : [ ],
+         |      "typeLayout" : {
+         |        "vectors" : [ {
+         |          "type" : "VALIDITY",
+         |          "typeBitWidth" : 1
+         |        }, {
+         |          "type" : "DATA",
+         |          "typeBitWidth" : 64
+         |        } ]
+         |      }
+         |    }, {
+         |      "name" : "e",
+         |      "type" : {
+         |        "name" : "int",
+         |        "isSigned" : true,
+         |        "bitWidth" : 64
+         |      },
+         |      "nullable" : false,
+         |      "children" : [ ],
+         |      "typeLayout" : {
+         |        "vectors" : [ {
+         |          "type" : "VALIDITY",
+         |          "typeBitWidth" : 1
+         |        }, {
+         |          "type" : "DATA",
+         |          "typeBitWidth" : 64
+         |        } ]
+         |      }
+         |    } ]
+         |  },
+         |  "batches" : [ {
+         |    "count" : 6,
+         |    "columns" : [ {
+         |      "name" : "a",
+         |      "count" : 6,
+         |      "VALIDITY" : [ 1, 1, 1, 1, 1, 1 ],
+         |      "DATA" : [ 1, 2, 3, 4, 5, 6 ]
+         |    }, {
+         |      "name" : "b",
+         |      "count" : 6,
+         |      "VALIDITY" : [ 1, 1, 1, 1, 1, 1 ],
+         |      "DATA" : [ 1.0, 2.0, 3.0, 4.0, 5.0, 6.0 ]
+         |    }, {
+         |      "name" : "c",
+         |      "count" : 6,
+         |      "VALIDITY" : [ 1, 1, 1, 1, 1, 1 ],
+         |      "DATA" : [ 1, 2, 3, 4, 5, 6 ]
+         |    }, {
+         |      "name" : "d",
+         |      "count" : 6,
+         |      "VALIDITY" : [ 1, 1, 1, 1, 1, 1 ],
+         |      "DATA" : [ 1.0, 2.0, 3.0, 4.0, 5.0, 6.0 ]
+         |    }, {
+         |      "name" : "e",
+         |      "count" : 6,
+         |      "VALIDITY" : [ 1, 1, 1, 1, 1, 1 ],
+         |      "DATA" : [ 1, 2, 3, 4, 5, 6 ]
+         |    } ]
+         |  } ]
+         |}
+       """.stripMargin
+
+    val data = List(1, 2, 3, 4, 5, 6)
+    val data_tuples = for (d <- data) yield {
+      (d.toShort, d.toFloat, d.toInt, d.toDouble, d.toLong)
+    }
+    val df = data_tuples.toDF("a", "b", "c", "d", "e")
+
+    collectAndValidate(df, json, "mixed_numeric_types.json")
+  }
+
+  test("string type conversion") {
+    val json =
+      s"""
+         |{
+         |  "schema" : {
+         |    "fields" : [ {
+         |      "name" : "upper_case",
+         |      "type" : {
+         |        "name" : "utf8"
+         |      },
+         |      "nullable" : true,
+         |      "children" : [ ],
+         |      "typeLayout" : {
+         |        "vectors" : [ {
+         |          "type" : "VALIDITY",
+         |          "typeBitWidth" : 1
+         |        }, {
+         |          "type" : "OFFSET",
+         |          "typeBitWidth" : 32
+         |        }, {
+         |          "type" : "DATA",
+         |          "typeBitWidth" : 8
+         |        } ]
+         |      }
+         |    }, {
+         |      "name" : "lower_case",
+         |      "type" : {
+         |        "name" : "utf8"
+         |      },
+         |      "nullable" : true,
+         |      "children" : [ ],
+         |      "typeLayout" : {
+         |        "vectors" : [ {
+         |          "type" : "VALIDITY",
+         |          "typeBitWidth" : 1
+         |        }, {
+         |          "type" : "OFFSET",
+         |          "typeBitWidth" : 32
+         |        }, {
+         |          "type" : "DATA",
+         |          "typeBitWidth" : 8
+         |        } ]
+         |      }
+         |    }, {
+         |      "name" : "null_str",
+         |      "type" : {
+         |        "name" : "utf8"
+         |      },
+         |      "nullable" : true,
+         |      "children" : [ ],
+         |      "typeLayout" : {
+         |        "vectors" : [ {
+         |          "type" : "VALIDITY",
+         |          "typeBitWidth" : 1
+         |        }, {
+         |          "type" : "OFFSET",
+         |          "typeBitWidth" : 32
+         |        }, {
+         |          "type" : "DATA",
+         |          "typeBitWidth" : 8
+         |        } ]
+         |      }
+         |    } ]
+         |  },
+         |  "batches" : [ {
+         |    "count" : 3,
+         |    "columns" : [ {
+         |      "name" : "upper_case",
+         |      "count" : 3,
+         |      "VALIDITY" : [ 1, 1, 1 ],
+         |      "OFFSET" : [ 0, 1, 2, 3 ],
+         |      "DATA" : [ "A", "B", "C" ]
+         |    }, {
+         |      "name" : "lower_case",
+         |      "count" : 3,
+         |      "VALIDITY" : [ 1, 1, 1 ],
+         |      "OFFSET" : [ 0, 1, 2, 3 ],
+         |      "DATA" : [ "a", "b", "c" ]
+         |    }, {
+         |      "name" : "null_str",
+         |      "count" : 3,
+         |      "VALIDITY" : [ 1, 1, 0 ],
+         |      "OFFSET" : [ 0, 2, 5, 5 ],
+         |      "DATA" : [ "ab", "CDE", "" ]
+         |    } ]
+         |  } ]
+         |}
+       """.stripMargin
+
+    val upperCase = Seq("A", "B", "C")
+    val lowerCase = Seq("a", "b", "c")
+    val nullStr = Seq("ab", "CDE", null)
+    val df = (upperCase, lowerCase, nullStr).zipped.toList
+      .toDF("upper_case", "lower_case", "null_str")
+
+    collectAndValidate(df, json, "stringData.json")
+  }
+
+  test("boolean type conversion") {
+    val json =
+      s"""
+         |{
+         |  "schema" : {
+         |    "fields" : [ {
+         |      "name" : "a_bool",
+         |      "type" : {
+         |        "name" : "bool"
+         |      },
+         |      "nullable" : false,
+         |      "children" : [ ],
+         |      "typeLayout" : {
+         |        "vectors" : [ {
+         |          "type" : "VALIDITY",
+         |          "typeBitWidth" : 1
+         |        }, {
+         |          "type" : "DATA",
+         |          "typeBitWidth" : 1
+         |        } ]
+         |      }
+         |    } ]
+         |  },
+         |  "batches" : [ {
+         |    "count" : 4,
+         |    "columns" : [ {
+         |      "name" : "a_bool",
+         |      "count" : 4,
+         |      "VALIDITY" : [ 1, 1, 1, 1 ],
+         |      "DATA" : [ true, true, false, true ]
+         |    } ]
+         |  } ]
+         |}
+       """.stripMargin
+    val df = Seq(true, true, false, true).toDF("a_bool")
+    collectAndValidate(df, json, "boolData.json")
+  }
+
+  test("byte type conversion") {
+    val json =
+      s"""
+         |{
+         |  "schema" : {
+         |    "fields" : [ {
+         |      "name" : "a_byte",
+         |      "type" : {
+         |        "name" : "int",
+         |        "isSigned" : true,
+         |        "bitWidth" : 8
+         |      },
+         |      "nullable" : false,
+         |      "children" : [ ],
+         |      "typeLayout" : {
+         |        "vectors" : [ {
+         |          "type" : "VALIDITY",
+         |          "typeBitWidth" : 1
+         |        }, {
+         |          "type" : "DATA",
+         |          "typeBitWidth" : 8
+         |        } ]
+         |      }
+         |    } ]
+         |  },
+         |  "batches" : [ {
+         |    "count" : 4,
+         |    "columns" : [ {
+         |      "name" : "a_byte",
+         |      "count" : 4,
+         |      "VALIDITY" : [ 1, 1, 1, 1 ],
+         |      "DATA" : [ 1, -1, 64, 127 ]
+         |    } ]
+         |  } ]
+         |}
+         |
+       """.stripMargin
+    val df = List[Byte](1.toByte, (-1).toByte, 64.toByte, Byte.MaxValue).toDF("a_byte")
+    collectAndValidate(df, json, "byteData.json")
+  }
+
+  test("binary type conversion") {
+    val json =
+      s"""
+         |{
+         |  "schema" : {
+         |    "fields" : [ {
+         |      "name" : "a_binary",
+         |      "type" : {
+         |        "name" : "binary"
+         |      },
+         |      "nullable" : true,
+         |      "children" : [ ],
+         |      "typeLayout" : {
+         |        "vectors" : [ {
+         |          "type" : "VALIDITY",
+         |          "typeBitWidth" : 1
+         |        }, {
+         |          "type" : "OFFSET",
+         |          "typeBitWidth" : 32
+         |        }, {
+         |          "type" : "DATA",
+         |          "typeBitWidth" : 8
+         |        } ]
+         |      }
+         |    } ]
+         |  },
+         |  "batches" : [ {
+         |    "count" : 3,
+         |    "columns" : [ {
+         |      "name" : "a_binary",
+         |      "count" : 3,
+         |      "VALIDITY" : [ 1, 1, 1 ],
+         |      "OFFSET" : [ 0, 3, 4, 6 ],
+         |      "DATA" : [ "616263", "64", "6566" ]
+         |    } ]
+         |  } ]
+         |}
+       """.stripMargin
+
+    val data = Seq("abc", "d", "ef")
+    val rdd = sparkContext.parallelize(data.map(s => Row(s.getBytes("utf-8"))))
+    val df = spark.createDataFrame(rdd, StructType(Seq(StructField("a_binary", BinaryType))))
+
+    collectAndValidate(df, json, "binaryData.json")
+  }
+
+  test("floating-point NaN") {
+    val json =
+      s"""
+         |{
+         |  "schema" : {
+         |    "fields" : [ {
+         |      "name" : "NaN_f",
+         |      "type" : {
+         |        "name" : "floatingpoint",
+         |        "precision" : "SINGLE"
+         |      },
+         |      "nullable" : false,
+         |      "children" : [ ],
+         |      "typeLayout" : {
+         |        "vectors" : [ {
+         |          "type" : "VALIDITY",
+         |          "typeBitWidth" : 1
+         |        }, {
+         |          "type" : "DATA",
+         |          "typeBitWidth" : 32
+         |        } ]
+         |      }
+         |    }, {
+         |      "name" : "NaN_d",
+         |      "type" : {
+         |        "name" : "floatingpoint",
+         |        "precision" : "DOUBLE"
+         |      },
+         |      "nullable" : false,
+         |      "children" : [ ],
+         |      "typeLayout" : {
+         |        "vectors" : [ {
+         |          "type" : "VALIDITY",
+         |          "typeBitWidth" : 1
+         |        }, {
+         |          "type" : "DATA",
+         |          "typeBitWidth" : 64
+         |        } ]
+         |      }
+         |    } ]
+         |  },
+         |  "batches" : [ {
+         |    "count" : 2,
+         |    "columns" : [ {
+         |      "name" : "NaN_f",
+         |      "count" : 2,
+         |      "VALIDITY" : [ 1, 1 ],
+         |      "DATA" : [ 1.2000000476837158, "NaN" ]
+         |    }, {
+         |      "name" : "NaN_d",
+         |      "count" : 2,
+         |      "VALIDITY" : [ 1, 1 ],
+         |      "DATA" : [ "NaN", 1.2 ]
+         |    } ]
+         |  } ]
+         |}
+       """.stripMargin
+
+    val fnan = Seq(1.2F, Float.NaN)
+    val dnan = Seq(Double.NaN, 1.2)
+    val df = fnan.zip(dnan).toDF("NaN_f", "NaN_d")
+
+    collectAndValidate(df, json, "nanData-floating_point.json")
+  }
+
+  test("partitioned DataFrame") {
+    val json1 =
+      s"""
+         |{
+         |  "schema" : {
+         |    "fields" : [ {
+         |      "name" : "a",
+         |      "type" : {
+         |        "name" : "int",
+         |        "isSigned" : true,
+         |        "bitWidth" : 32
+         |      },
+         |      "nullable" : false,
+         |      "children" : [ ],
+         |      "typeLayout" : {
+         |        "vectors" : [ {
+         |          "type" : "VALIDITY",
+         |          "typeBitWidth" : 1
+         |        }, {
+         |          "type" : "DATA",
+         |          "typeBitWidth" : 32
+         |        } ]
+         |      }
+         |    }, {
+         |      "name" : "b",
+         |      "type" : {
+         |        "name" : "int",
+         |        "isSigned" : true,
+         |        "bitWidth" : 32
+         |      },
+         |      "nullable" : false,
+         |      "children" : [ ],
+         |      "typeLayout" : {
+         |        "vectors" : [ {
+         |          "type" : "VALIDITY",
+         |          "typeBitWidth" : 1
+         |        }, {
+         |          "type" : "DATA",
+         |          "typeBitWidth" : 32
+         |        } ]
+         |      }
+         |    } ]
+         |  },
+         |  "batches" : [ {
+         |    "count" : 3,
+         |    "columns" : [ {
+         |      "name" : "a",
+         |      "count" : 3,
+         |      "VALIDITY" : [ 1, 1, 1 ],
+         |      "DATA" : [ 1, 1, 2 ]
+         |    }, {
+         |      "name" : "b",
+         |      "count" : 3,
+         |      "VALIDITY" : [ 1, 1, 1 ],
+         |      "DATA" : [ 1, 2, 1 ]
+         |    } ]
+         |  } ]
+         |}
+       """.stripMargin
+    val json2 =
+      s"""
+         |{
+         |  "schema" : {
+         |    "fields" : [ {
+         |      "name" : "a",
+         |      "type" : {
+         |        "name" : "int",
+         |        "isSigned" : true,
+         |        "bitWidth" : 32
+         |      },
+         |      "nullable" : false,
+         |      "children" : [ ],
+         |      "typeLayout" : {
+         |        "vectors" : [ {
+         |          "type" : "VALIDITY",
+         |          "typeBitWidth" : 1
+         |        }, {
+         |          "type" : "DATA",
+         |          "typeBitWidth" : 32
+         |        } ]
+         |      }
+         |    }, {
+         |      "name" : "b",
+         |      "type" : {
+         |        "name" : "int",
+         |        "isSigned" : true,
+         |        "bitWidth" : 32
+         |      },
+         |      "nullable" : false,
+         |      "children" : [ ],
+         |      "typeLayout" : {
+         |        "vectors" : [ {
+         |          "type" : "VALIDITY",
+         |          "typeBitWidth" : 1
+         |        }, {
+         |          "type" : "DATA",
+         |          "typeBitWidth" : 32
+         |        } ]
+         |      }
+         |    } ]
+         |  },
+         |  "batches" : [ {
+         |    "count" : 3,
+         |    "columns" : [ {
+         |      "name" : "a",
+         |      "count" : 3,
+         |      "VALIDITY" : [ 1, 1, 1 ],
+         |      "DATA" : [ 2, 3, 3 ]
+         |    }, {
+         |      "name" : "b",
+         |      "count" : 3,
+         |      "VALIDITY" : [ 1, 1, 1 ],
+         |      "DATA" : [ 2, 1, 2 ]
+         |    } ]
+         |  } ]
+         |}
+       """.stripMargin
+
+    val arrowPayloads = testData2.toArrowPayload.collect()
+    // NOTE: testData2 should have 2 partitions -> 2 arrow batches in payload
+    assert(arrowPayloads.length === 2)
+    val schema = testData2.schema
+
+    val tempFile1 = new File(tempDataPath, "testData2-ints-part1.json")
+    val tempFile2 = new File(tempDataPath, "testData2-ints-part2.json")
+    Files.write(json1, tempFile1, StandardCharsets.UTF_8)
+    Files.write(json2, tempFile2, StandardCharsets.UTF_8)
+
+    validateConversion(schema, arrowPayloads(0), tempFile1)
+    validateConversion(schema, arrowPayloads(1), tempFile2)
+  }
+
+  test("empty frame collect") {
+    val arrowPayload = spark.emptyDataFrame.toArrowPayload.collect()
+    assert(arrowPayload.isEmpty)
+
+    val filteredDF = List[Int](1, 2, 3, 4, 5, 6).toDF("i")
+    val filteredArrowPayload = filteredDF.filter("i < 0").toArrowPayload.collect()
+    assert(filteredArrowPayload.isEmpty)
+  }
+
+  test("empty partition collect") {
+    val emptyPart = spark.sparkContext.parallelize(Seq(1), 2).toDF("i")
+    val arrowPayloads = emptyPart.toArrowPayload.collect()
+    assert(arrowPayloads.length === 1)
+    val allocator = new RootAllocator(Long.MaxValue)
+    val arrowRecordBatches = arrowPayloads.map(_.loadBatch(allocator))
+    assert(arrowRecordBatches.head.getLength == 1)
+    arrowRecordBatches.foreach(_.close())
+    allocator.close()
+  }
+
+  test("max records in batch conf") {
+    val totalRecords = 10
+    val maxRecordsPerBatch = 3
+    spark.conf.set("spark.sql.execution.arrow.maxRecordsPerBatch", maxRecordsPerBatch)
+    val df = spark.sparkContext.parallelize(1 to totalRecords, 2).toDF("i")
+    val arrowPayloads = df.toArrowPayload.collect()
+    val allocator = new RootAllocator(Long.MaxValue)
+    val arrowRecordBatches = arrowPayloads.map(_.loadBatch(allocator))
+    var recordCount = 0
+    arrowRecordBatches.foreach { batch =>
+      assert(batch.getLength > 0)
+      assert(batch.getLength <= maxRecordsPerBatch)
+      recordCount += batch.getLength
+      batch.close()
+    }
+    assert(recordCount == totalRecords)
+    allocator.close()
+    spark.conf.unset("spark.sql.execution.arrow.maxRecordsPerBatch")
+  }
+
+  testQuietly("unsupported types") {
+    def runUnsupported(block: => Unit): Unit = {
+      val msg = intercept[SparkException] {
+        block
+      }
+      assert(msg.getMessage.contains("Unsupported data type"))
+      assert(msg.getCause.getClass === classOf[UnsupportedOperationException])
+    }
+
+    runUnsupported { decimalData.toArrowPayload.collect() }
+    runUnsupported { arrayData.toDF().toArrowPayload.collect() }
+    runUnsupported { mapData.toDF().toArrowPayload.collect() }
+    runUnsupported { complexData.toArrowPayload.collect() }
+
+    val sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss.SSS z", Locale.US)
+    val d1 = new Date(sdf.parse("2015-04-08 13:10:15.000 UTC").getTime)
+    val d2 = new Date(sdf.parse("2016-05-09 13:10:15.000 UTC").getTime)
+    runUnsupported { Seq(d1, d2).toDF("date").toArrowPayload.collect() }
+
+    val ts1 = new Timestamp(sdf.parse("2013-04-08 01:10:15.567 UTC").getTime)
+    val ts2 = new Timestamp(sdf.parse("2013-04-08 13:10:10.789 UTC").getTime)
+    runUnsupported { Seq(ts1, ts2).toDF("timestamp").toArrowPayload.collect() }
+  }
+
+  test("test Arrow Validator") {
+    val json =
+      s"""
+         |{
+         |  "schema" : {
+         |    "fields" : [ {
+         |      "name" : "a_i",
+         |      "type" : {
+         |        "name" : "int",
+         |        "isSigned" : true,
+         |        "bitWidth" : 32
+         |      },
+         |      "nullable" : false,
+         |      "children" : [ ],
+         |      "typeLayout" : {
+         |        "vectors" : [ {
+         |          "type" : "VALIDITY",
+         |          "typeBitWidth" : 1
+         |        }, {
+         |          "type" : "DATA",
+         |          "typeBitWidth" : 32
+         |        } ]
+         |      }
+         |    }, {
+         |      "name" : "b_i",
+         |      "type" : {
+         |        "name" : "int",
+         |        "isSigned" : true,
+         |        "bitWidth" : 32
+         |      },
+         |      "nullable" : true,
+         |      "children" : [ ],
+         |      "typeLayout" : {
+         |        "vectors" : [ {
+         |          "type" : "VALIDITY",
+         |          "typeBitWidth" : 1
+         |        }, {
+         |          "type" : "DATA",
+         |          "typeBitWidth" : 32
+         |        } ]
+         |      }
+         |    } ]
+         |  },
+         |  "batches" : [ {
+         |    "count" : 6,
+         |    "columns" : [ {
+         |      "name" : "a_i",
+         |      "count" : 6,
+         |      "VALIDITY" : [ 1, 1, 1, 1, 1, 1 ],
+         |      "DATA" : [ 1, -1, 2, -2, 2147483647, -2147483648 ]
+         |    }, {
+         |      "name" : "b_i",
+         |      "count" : 6,
+         |      "VALIDITY" : [ 1, 0, 0, 1, 0, 1 ],
+         |      "DATA" : [ 1, 0, 0, -2, 0, -2147483648 ]
+         |    } ]
+         |  } ]
+         |}
+       """.stripMargin
+    val json_diff_col_order =
+      s"""
+         |{
+         |  "schema" : {
+         |    "fields" : [ {
+         |      "name" : "b_i",
+         |      "type" : {
+         |        "name" : "int",
+         |        "isSigned" : true,
+         |        "bitWidth" : 32
+         |      },
+         |      "nullable" : true,
+         |      "children" : [ ],
+         |      "typeLayout" : {
+         |        "vectors" : [ {
+         |          "type" : "VALIDITY",
+         |          "typeBitWidth" : 1
+         |        }, {
+         |          "type" : "DATA",
+         |          "typeBitWidth" : 32
+         |        } ]
+         |      }
+         |    }, {
+         |      "name" : "a_i",
+         |      "type" : {
+         |        "name" : "int",
+         |        "isSigned" : true,
+         |        "bitWidth" : 32
+         |      },
+         |      "nullable" : false,
+         |      "children" : [ ],
+         |      "typeLayout" : {
+         |        "vectors" : [ {
+         |          "type" : "VALIDITY",
+         |          "typeBitWidth" : 1
+         |        }, {
+         |          "type" : "DATA",
+         |          "typeBitWidth" : 32
+         |        } ]
+         |      }
+         |    } ]
+         |  },
+         |  "batches" : [ {
+         |    "count" : 6,
+         |    "columns" : [ {
+         |      "name" : "a_i",
+         |      "count" : 6,
+         |      "VALIDITY" : [ 1, 1, 1, 1, 1, 1 ],
+         |      "DATA" : [ 1, -1, 2, -2, 2147483647, -2147483648 ]
+         |    }, {
+         |      "name" : "b_i",
+         |      "count" : 6,
+         |      "VALIDITY" : [ 1, 0, 0, 1, 0, 1 ],
+         |      "DATA" : [ 1, 0, 0, -2, 0, -2147483648 ]
+         |    } ]
+         |  } ]
+         |}
+       """.stripMargin
+
+    val a_i = List[Int](1, -1, 2, -2, 2147483647, -2147483648)
+    val b_i = List[Option[Int]](Some(1), None, None, Some(-2), None, Some(-2147483648))
+    val df = a_i.zip(b_i).toDF("a_i", "b_i")
+
+    // Different schema
+    intercept[IllegalArgumentException] {
+      collectAndValidate(df, json_diff_col_order, "validator_diff_schema.json")
+    }
+
+    // Different values
+    intercept[IllegalArgumentException] {
+      collectAndValidate(df.sort($"a_i".desc), json, "validator_diff_values.json")
+    }
+  }
+
+  /** Test that a converted DataFrame to Arrow record batch equals batch read from JSON file */
+  private def collectAndValidate(df: DataFrame, json: String, file: String): Unit = {
+    // NOTE: coalesce to single partition because can only load 1 batch in validator
+    val arrowPayload = df.coalesce(1).toArrowPayload.collect().head
+    val tempFile = new File(tempDataPath, file)
+    Files.write(json, tempFile, StandardCharsets.UTF_8)
+    validateConversion(df.schema, arrowPayload, tempFile)
+  }
+
+  private def validateConversion(
+      sparkSchema: StructType,
+      arrowPayload: ArrowPayload,
+      jsonFile: File): Unit = {
+    val allocator = new RootAllocator(Long.MaxValue)
+    val jsonReader = new JsonFileReader(jsonFile, allocator)
+
+    val arrowSchema = ArrowConverters.schemaToArrowSchema(sparkSchema)
+    val jsonSchema = jsonReader.start()
+    Validator.compareSchemas(arrowSchema, jsonSchema)
+
+    val arrowRoot = VectorSchemaRoot.create(arrowSchema, allocator)
+    val vectorLoader = new VectorLoader(arrowRoot)
+    val arrowRecordBatch = arrowPayload.loadBatch(allocator)
+    vectorLoader.load(arrowRecordBatch)
+    val jsonRoot = jsonReader.read()
+    Validator.compareVectorSchemaRoot(arrowRoot, jsonRoot)
+
+    jsonRoot.close()
+    jsonReader.close()
+    arrowRecordBatch.close()
+    arrowRoot.close()
+    allocator.close()
+  }
+}


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