[spark] Implement SupportsReportStatistics for PaimonFormatTableBaseScan

paimon-spark/paimon-spark-common/src/main/scala/org/apache/paimon/spark/FormatTableStatistics.scala

@@ -0,0 +1,47 @@
+/*
+ * 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.paimon.spark
+
+import org.apache.paimon.table.format.FormatDataSplit
+import org.apache.paimon.types.RowType
+
+import org.apache.spark.sql.connector.read.Statistics
+
+import java.util.OptionalLong
+
+import scala.collection.JavaConverters._
+
+case class FormatTableStatistics[T <: PaimonFormatTableBaseScan](scan: T) extends Statistics {
+
+  private lazy val fileTotalSize: Long =
+    scan.getOriginSplits.map(_.asInstanceOf[FormatDataSplit]).map(_.length()).sum
+
+  override def sizeInBytes(): OptionalLong = {
+    val size = fileTotalSize /
+      estimateRowSize(scan.tableRowType) *
+      estimateRowSize(scan.readTableRowType)
+    OptionalLong.of(size)
+  }
+
+  private def estimateRowSize(rowType: RowType): Long = {
+    rowType.getFields.asScala.map(_.`type`().defaultSize().toLong).sum
+  }
+
+  override def numRows(): OptionalLong = OptionalLong.empty()
+}

paimon-spark/paimon-spark-common/src/main/scala/org/apache/paimon/spark/PaimonFormatTableBaseScan.scala

@@ -24,7 +24,7 @@ import org.apache.paimon.table.FormatTable
 import org.apache.paimon.table.source.Split
 
 import org.apache.spark.sql.connector.metric.{CustomMetric, CustomTaskMetric}
-import org.apache.spark.sql.connector.read.Batch
+import org.apache.spark.sql.connector.read.{Batch, Statistics, SupportsReportStatistics}
 import org.apache.spark.sql.types.StructType
 
 import scala.collection.JavaConverters._
@@ -36,6 +36,7 @@ abstract class PaimonFormatTableBaseScan(
     filters: Seq[Predicate],
     pushDownLimit: Option[Int])
   extends ColumnPruningAndPushDown
+  with SupportsReportStatistics
   with ScanHelper {
 
   override val coreOptions: CoreOptions = CoreOptions.fromMap(table.options())
@@ -65,6 +66,10 @@ abstract class PaimonFormatTableBaseScan(
     PaimonBatch(lazyInputPartitions, readBuilder, coreOptions.blobAsDescriptor(), metadataColumns)
   }
 
+  override def estimateStatistics(): Statistics = {
+    FormatTableStatistics(this)
+  }
+
   override def supportedCustomMetrics: Array[CustomMetric] = {
     Array(
       PaimonNumSplitMetric(),

paimon-spark/paimon-spark-ut/src/test/scala/org/apache/paimon/spark/sql/FormatTableTestBase.scala

@@ -155,4 +155,15 @@ abstract class FormatTableTestBase extends PaimonHiveTestBase {
       assert(row.toString().contains("'csv.field-delimiter' = ';'"))
     }
   }
+
+  test("Format table: broadcast join for small table") {
+    withTable("t") {
+      sql("CREATE TABLE t1 (f0 INT, f1 INT) USING CSV TBLPROPERTIES ('file.compression'='none')")
+      sql("CREATE TABLE t2 (f0 INT, f2 INT) USING CSV TBLPROPERTIES ('file.compression'='none')")
+      sql("INSERT INTO t1 VALUES (1, 1)")
+      sql("INSERT INTO t2 VALUES (1, 1)")
+      val df = sql("SELECT t1.f0, t1.f1, t2.f2 FROM t1, t2 WHERE t1.f0 = t2.f0")
+      assert(df.queryExecution.executedPlan.toString().contains("BroadcastExchange"))
+    }
+  }
 }