[SPARK-15639] [SPARK-16321] [SQL] Push down filter at RowGroups level…

… for parquet reader

The base class `SpecificParquetRecordReaderBase` used for vectorized parquet reader will try to get pushed-down filters from the given configuration. This pushed-down filters are used for RowGroups-level filtering. However, we don't set up the filters to push down into the configuration. In other words, the filters are not actually pushed down to do RowGroups-level filtering. This patch is to fix this and tries to set up the filters for pushing down to configuration for the reader.

The benchmark that excludes the time of writing Parquet file:

    test("Benchmark for Parquet") {
      val N = 500 << 12
        withParquetTable((0 until N).map(i => (101, i)), "t") {
          val benchmark = new Benchmark("Parquet reader", N)
          benchmark.addCase("reading Parquet file", 10) { iter =>
            sql("SELECT _1 FROM t where t._1 < 100").collect()
          }
          benchmark.run()
      }
    }

`withParquetTable` in default will run tests for vectorized reader non-vectorized readers. I only let it run vectorized reader.

When we set the block size of parquet as 1024 to have multiple row groups. The benchmark is:

Before this patch:

The retrieved row groups: 8063

    Java HotSpot(TM) 64-Bit Server VM 1.8.0_71-b15 on Linux 3.19.0-25-generic
    Intel(R) Core(TM) i7-5557U CPU  3.10GHz
    Parquet reader:                          Best/Avg Time(ms)    Rate(M/s)   Per Row(ns)   Relative
    ------------------------------------------------------------------------------------------------
    reading Parquet file                           825 / 1233          2.5         402.6       1.0X

After this patch:

The retrieved row groups: 0

    Java HotSpot(TM) 64-Bit Server VM 1.8.0_71-b15 on Linux 3.19.0-25-generic
    Intel(R) Core(TM) i7-5557U CPU  3.10GHz
    Parquet reader:                          Best/Avg Time(ms)    Rate(M/s)   Per Row(ns)   Relative
    ------------------------------------------------------------------------------------------------
    reading Parquet file                           306 /  503          6.7         149.6       1.0X

Next, I run the benchmark for non-pushdown case using the same benchmark code but with disabled pushdown configuration. This time the parquet block size is default value.

Before this patch:

    Java HotSpot(TM) 64-Bit Server VM 1.8.0_71-b15 on Linux 3.19.0-25-generic
    Intel(R) Core(TM) i7-5557U CPU  3.10GHz
    Parquet reader:                          Best/Avg Time(ms)    Rate(M/s)   Per Row(ns)   Relative
    ------------------------------------------------------------------------------------------------
    reading Parquet file                           136 /  238         15.0          66.5       1.0X

After this patch:

    Java HotSpot(TM) 64-Bit Server VM 1.8.0_71-b15 on Linux 3.19.0-25-generic
    Intel(R) Core(TM) i7-5557U CPU  3.10GHz
    Parquet reader:                          Best/Avg Time(ms)    Rate(M/s)   Per Row(ns)   Relative
    ------------------------------------------------------------------------------------------------
    reading Parquet file                           124 /  193         16.5          60.7       1.0X

For non-pushdown case, from the results, I think this patch doesn't affect normal code path.

I've manually output the `totalRowCount` in `SpecificParquetRecordReaderBase` to see if this patch actually filter the row-groups. When running the above benchmark:

After this patch:
    `totalRowCount = 0`

Before this patch:
    `totalRowCount = 1024000`

Existing tests should be passed.

Author: Liang-Chi Hsieh <[email protected]>

Closes #13701 from viirya/vectorized-reader-push-down-filter2.

(cherry picked from commit 19af298)
Signed-off-by: Davies Liu <[email protected]>

core/src/main/scala/org/apache/spark/executor/TaskMetrics.scala

@@ -225,6 +225,15 @@ class TaskMetrics private[spark] () extends Serializable {
   }
 
   private[spark] def accumulators(): Seq[AccumulatorV2[_, _]] = internalAccums ++ externalAccums
+
+  /**
+   * Looks for a registered accumulator by accumulator name.
+   */
+  private[spark] def lookForAccumulatorByName(name: String): Option[AccumulatorV2[_, _]] = {
+    accumulators.find { acc =>
+      acc.name.isDefined && acc.name.get == name
+    }
+  }
 }
 
 

core/src/main/scala/org/apache/spark/util/AccumulatorV2.scala

@@ -23,6 +23,8 @@ import java.util.ArrayList
 import java.util.concurrent.ConcurrentHashMap
 import java.util.concurrent.atomic.AtomicLong
 
+import scala.collection.JavaConverters._
+
 import org.apache.spark.{InternalAccumulator, SparkContext, TaskContext}
 import org.apache.spark.scheduler.AccumulableInfo
 
@@ -257,6 +259,16 @@ private[spark] object AccumulatorContext {
     originals.clear()
   }
 
+  /**
+   * Looks for a registered accumulator by accumulator name.
+   */
+  private[spark] def lookForAccumulatorByName(name: String): Option[AccumulatorV2[_, _]] = {
+    originals.values().asScala.find { ref =>
+      val acc = ref.get
+      acc != null && acc.name.isDefined && acc.name.get == name
+    }.map(_.get)
+  }
+
   // Identifier for distinguishing SQL metrics from other accumulators
   private[spark] val SQL_ACCUM_IDENTIFIER = "sql"
 }

sql/core/src/main/java/org/apache/spark/sql/execution/datasources/parquet/SpecificParquetRecordReaderBase.java

@@ -31,6 +31,8 @@
 import java.util.Map;
 import java.util.Set;
 
+import scala.Option;
+
 import static org.apache.parquet.filter2.compat.RowGroupFilter.filterRowGroups;
 import static org.apache.parquet.format.converter.ParquetMetadataConverter.NO_FILTER;
 import static org.apache.parquet.format.converter.ParquetMetadataConverter.range;
@@ -59,8 +61,12 @@
 import org.apache.parquet.hadoop.util.ConfigurationUtil;
 import org.apache.parquet.schema.MessageType;
 import org.apache.parquet.schema.Types;
+import org.apache.spark.TaskContext;
+import org.apache.spark.TaskContext$;
 import org.apache.spark.sql.types.StructType;
 import org.apache.spark.sql.types.StructType$;
+import org.apache.spark.util.AccumulatorV2;
+import org.apache.spark.util.LongAccumulator;
 
 /**
  * Base class for custom RecordReaders for Parquet that directly materialize to `T`.
@@ -144,6 +150,18 @@ public void initialize(InputSplit inputSplit, TaskAttemptContext taskAttemptCont
     for (BlockMetaData block : blocks) {
       this.totalRowCount += block.getRowCount();
     }
+
+    // For test purpose.
+    // If the predefined accumulator exists, the row group number to read will be updated
+    // to the accumulator. So we can check if the row groups are filtered or not in test case.
+    TaskContext taskContext = TaskContext$.MODULE$.get();
+    if (taskContext != null) {
+      Option<AccumulatorV2<?, ?>> accu = (Option<AccumulatorV2<?, ?>>) taskContext.taskMetrics()
+        .lookForAccumulatorByName("numRowGroups");
+      if (accu.isDefined()) {
+        ((LongAccumulator)accu.get()).add((long)blocks.size());
+      }
+    }
   }
 
   /**

sql/core/src/main/scala/org/apache/spark/sql/execution/datasources/parquet/ParquetFileFormat.scala

@@ -46,6 +46,7 @@ import org.apache.spark.sql.catalyst.expressions.codegen.GenerateUnsafeProjectio
 import org.apache.spark.sql.catalyst.parser.LegacyTypeStringParser
 import org.apache.spark.sql.execution.command.CreateDataSourceTableUtils
 import org.apache.spark.sql.execution.datasources._
+import org.apache.spark.sql.execution.metric.SQLMetric
 import org.apache.spark.sql.internal.SQLConf
 import org.apache.spark.sql.sources._
 import org.apache.spark.sql.types._
@@ -355,6 +356,11 @@ private[sql] class ParquetFileFormat
       val hadoopAttemptContext =
         new TaskAttemptContextImpl(broadcastedHadoopConf.value.value, attemptId)
 
+      // Try to push down filters when filter push-down is enabled.
+      // Notice: This push-down is RowGroups level, not individual records.
+      if (pushed.isDefined) {
+        ParquetInputFormat.setFilterPredicate(hadoopAttemptContext.getConfiguration, pushed.get)
+      }
       val parquetReader = if (enableVectorizedReader) {
         val vectorizedReader = new VectorizedParquetRecordReader()
         vectorizedReader.initialize(split, hadoopAttemptContext)

sql/core/src/test/scala/org/apache/spark/sql/execution/datasources/parquet/ParquetFilterSuite.scala

@@ -32,6 +32,7 @@ import org.apache.spark.sql.functions._
 import org.apache.spark.sql.internal.SQLConf
 import org.apache.spark.sql.test.SharedSQLContext
 import org.apache.spark.sql.types._
+import org.apache.spark.util.{AccumulatorContext, LongAccumulator}
 
 /**
  * A test suite that tests Parquet filter2 API based filter pushdown optimization.
@@ -370,73 +371,75 @@ class ParquetFilterSuite extends QueryTest with ParquetTest with SharedSQLContex
 
   test("SPARK-11103: Filter applied on merged Parquet schema with new column fails") {
     import testImplicits._
-
-    withSQLConf(SQLConf.PARQUET_FILTER_PUSHDOWN_ENABLED.key -> "true",
-      SQLConf.PARQUET_SCHEMA_MERGING_ENABLED.key -> "true") {
-      withTempPath { dir =>
-        val pathOne = s"${dir.getCanonicalPath}/table1"
-        (1 to 3).map(i => (i, i.toString)).toDF("a", "b").write.parquet(pathOne)
-        val pathTwo = s"${dir.getCanonicalPath}/table2"
-        (1 to 3).map(i => (i, i.toString)).toDF("c", "b").write.parquet(pathTwo)
-
-        // If the "c = 1" filter gets pushed down, this query will throw an exception which
-        // Parquet emits. This is a Parquet issue (PARQUET-389).
-        val df = spark.read.parquet(pathOne, pathTwo).filter("c = 1").selectExpr("c", "b", "a")
-        checkAnswer(
-          df,
-          Row(1, "1", null))
-
-        // The fields "a" and "c" only exist in one Parquet file.
-        assert(df.schema("a").metadata.getBoolean(StructType.metadataKeyForOptionalField))
-        assert(df.schema("c").metadata.getBoolean(StructType.metadataKeyForOptionalField))
-
-        val pathThree = s"${dir.getCanonicalPath}/table3"
-        df.write.parquet(pathThree)
-
-        // We will remove the temporary metadata when writing Parquet file.
-        val schema = spark.read.parquet(pathThree).schema
-        assert(schema.forall(!_.metadata.contains(StructType.metadataKeyForOptionalField)))
-
-        val pathFour = s"${dir.getCanonicalPath}/table4"
-        val dfStruct = sparkContext.parallelize(Seq((1, 1))).toDF("a", "b")
-        dfStruct.select(struct("a").as("s")).write.parquet(pathFour)
-
-        val pathFive = s"${dir.getCanonicalPath}/table5"
-        val dfStruct2 = sparkContext.parallelize(Seq((1, 1))).toDF("c", "b")
-        dfStruct2.select(struct("c").as("s")).write.parquet(pathFive)
-
-        // If the "s.c = 1" filter gets pushed down, this query will throw an exception which
-        // Parquet emits.
-        val dfStruct3 = spark.read.parquet(pathFour, pathFive).filter("s.c = 1")
-          .selectExpr("s")
-        checkAnswer(dfStruct3, Row(Row(null, 1)))
-
-        // The fields "s.a" and "s.c" only exist in one Parquet file.
-        val field = dfStruct3.schema("s").dataType.asInstanceOf[StructType]
-        assert(field("a").metadata.getBoolean(StructType.metadataKeyForOptionalField))
-        assert(field("c").metadata.getBoolean(StructType.metadataKeyForOptionalField))
-
-        val pathSix = s"${dir.getCanonicalPath}/table6"
-        dfStruct3.write.parquet(pathSix)
-
-        // We will remove the temporary metadata when writing Parquet file.
-        val forPathSix = spark.read.parquet(pathSix).schema
-        assert(forPathSix.forall(!_.metadata.contains(StructType.metadataKeyForOptionalField)))
-
-        // sanity test: make sure optional metadata field is not wrongly set.
-        val pathSeven = s"${dir.getCanonicalPath}/table7"
-        (1 to 3).map(i => (i, i.toString)).toDF("a", "b").write.parquet(pathSeven)
-        val pathEight = s"${dir.getCanonicalPath}/table8"
-        (4 to 6).map(i => (i, i.toString)).toDF("a", "b").write.parquet(pathEight)
-
-        val df2 = spark.read.parquet(pathSeven, pathEight).filter("a = 1").selectExpr("a", "b")
-        checkAnswer(
-          df2,
-          Row(1, "1"))
-
-        // The fields "a" and "b" exist in both two Parquet files. No metadata is set.
-        assert(!df2.schema("a").metadata.contains(StructType.metadataKeyForOptionalField))
-        assert(!df2.schema("b").metadata.contains(StructType.metadataKeyForOptionalField))
+    Seq("true", "false").map { vectorized =>
+      withSQLConf(SQLConf.PARQUET_FILTER_PUSHDOWN_ENABLED.key -> "true",
+        SQLConf.PARQUET_SCHEMA_MERGING_ENABLED.key -> "true",
+        SQLConf.PARQUET_VECTORIZED_READER_ENABLED.key -> vectorized) {
+        withTempPath { dir =>
+          val pathOne = s"${dir.getCanonicalPath}/table1"
+          (1 to 3).map(i => (i, i.toString)).toDF("a", "b").write.parquet(pathOne)
+          val pathTwo = s"${dir.getCanonicalPath}/table2"
+          (1 to 3).map(i => (i, i.toString)).toDF("c", "b").write.parquet(pathTwo)
+
+          // If the "c = 1" filter gets pushed down, this query will throw an exception which
+          // Parquet emits. This is a Parquet issue (PARQUET-389).
+          val df = spark.read.parquet(pathOne, pathTwo).filter("c = 1").selectExpr("c", "b", "a")
+          checkAnswer(
+            df,
+            Row(1, "1", null))
+
+          // The fields "a" and "c" only exist in one Parquet file.
+          assert(df.schema("a").metadata.getBoolean(StructType.metadataKeyForOptionalField))
+          assert(df.schema("c").metadata.getBoolean(StructType.metadataKeyForOptionalField))
+
+          val pathThree = s"${dir.getCanonicalPath}/table3"
+          df.write.parquet(pathThree)
+
+          // We will remove the temporary metadata when writing Parquet file.
+          val schema = spark.read.parquet(pathThree).schema
+          assert(schema.forall(!_.metadata.contains(StructType.metadataKeyForOptionalField)))
+
+          val pathFour = s"${dir.getCanonicalPath}/table4"
+          val dfStruct = sparkContext.parallelize(Seq((1, 1))).toDF("a", "b")
+          dfStruct.select(struct("a").as("s")).write.parquet(pathFour)
+
+          val pathFive = s"${dir.getCanonicalPath}/table5"
+          val dfStruct2 = sparkContext.parallelize(Seq((1, 1))).toDF("c", "b")
+          dfStruct2.select(struct("c").as("s")).write.parquet(pathFive)
+
+          // If the "s.c = 1" filter gets pushed down, this query will throw an exception which
+          // Parquet emits.
+          val dfStruct3 = spark.read.parquet(pathFour, pathFive).filter("s.c = 1")
+            .selectExpr("s")
+          checkAnswer(dfStruct3, Row(Row(null, 1)))
+
+          // The fields "s.a" and "s.c" only exist in one Parquet file.
+          val field = dfStruct3.schema("s").dataType.asInstanceOf[StructType]
+          assert(field("a").metadata.getBoolean(StructType.metadataKeyForOptionalField))
+          assert(field("c").metadata.getBoolean(StructType.metadataKeyForOptionalField))
+
+          val pathSix = s"${dir.getCanonicalPath}/table6"
+          dfStruct3.write.parquet(pathSix)
+
+          // We will remove the temporary metadata when writing Parquet file.
+          val forPathSix = spark.read.parquet(pathSix).schema
+          assert(forPathSix.forall(!_.metadata.contains(StructType.metadataKeyForOptionalField)))
+
+          // sanity test: make sure optional metadata field is not wrongly set.
+          val pathSeven = s"${dir.getCanonicalPath}/table7"
+          (1 to 3).map(i => (i, i.toString)).toDF("a", "b").write.parquet(pathSeven)
+          val pathEight = s"${dir.getCanonicalPath}/table8"
+          (4 to 6).map(i => (i, i.toString)).toDF("a", "b").write.parquet(pathEight)
+
+          val df2 = spark.read.parquet(pathSeven, pathEight).filter("a = 1").selectExpr("a", "b")
+          checkAnswer(
+            df2,
+            Row(1, "1"))
+
+          // The fields "a" and "b" exist in both two Parquet files. No metadata is set.
+          assert(!df2.schema("a").metadata.contains(StructType.metadataKeyForOptionalField))
+          assert(!df2.schema("b").metadata.contains(StructType.metadataKeyForOptionalField))
+        }
       }
     }
   }
@@ -559,4 +562,32 @@ class ParquetFilterSuite extends QueryTest with ParquetTest with SharedSQLContex
       assert(df.filter("_1 IS NOT NULL").count() === 4)
     }
   }
+
+  test("Fiters should be pushed down for vectorized Parquet reader at row group level") {
+    import testImplicits._
+
+    withSQLConf(SQLConf.PARQUET_VECTORIZED_READER_ENABLED.key -> "true",
+        SQLConf.WHOLESTAGE_CODEGEN_ENABLED.key -> "false") {
+      withTempPath { dir =>
+        val path = s"${dir.getCanonicalPath}/table"
+        (1 to 1024).map(i => (101, i)).toDF("a", "b").write.parquet(path)
+
+        Seq(("true", (x: Long) => x == 0), ("false", (x: Long) => x > 0)).map { case (push, func) =>
+          withSQLConf(SQLConf.PARQUET_FILTER_PUSHDOWN_ENABLED.key -> push) {
+            val accu = new LongAccumulator
+            accu.register(sparkContext, Some("numRowGroups"))
+
+            val df = spark.read.parquet(path).filter("a < 100")
+            df.foreachPartition(_.foreach(v => accu.add(0)))
+            df.collect
+
+            val numRowGroups = AccumulatorContext.lookForAccumulatorByName("numRowGroups")
+            assert(numRowGroups.isDefined)
+            assert(func(numRowGroups.get.asInstanceOf[LongAccumulator].value))
+            AccumulatorContext.remove(accu.id)
+          }
+        }
+      }
+    }
+  }
 }