PLUGIN-1925: Introduce Custom BigDecimal Splitter

database-commons/src/main/java/io/cdap/plugin/db/source/DataDrivenETLDBInputFormat.java

@@ -28,6 +28,7 @@
 import org.apache.hadoop.mapreduce.TaskAttemptContext;
 import org.apache.hadoop.mapreduce.lib.db.DBConfiguration;
 import org.apache.hadoop.mapreduce.lib.db.DBInputFormat;
+import org.apache.hadoop.mapreduce.lib.db.DBSplitter;
 import org.apache.hadoop.mapreduce.lib.db.DBWritable;
 import org.apache.hadoop.mapreduce.lib.db.DataDrivenDBInputFormat;
 import org.slf4j.Logger;
@@ -39,6 +40,7 @@
 import java.sql.DriverManager;
 import java.sql.SQLException;
 import java.sql.Statement;
+import java.sql.Types;
 import java.util.Properties;
 
 /**
@@ -128,6 +130,15 @@ public Connection createConnection() {
     return getConnection();
   }
 
+  @Override
+  protected DBSplitter getSplitter(int sqlDataType) {
+    // Use SafeBigDecimalSplitter for columns having high precision decimal or numeric columns
+    if (sqlDataType == Types.NUMERIC || sqlDataType == Types.DECIMAL) {
+      return new SafeBigDecimalSplitter();
+    }
+    return super.getSplitter(sqlDataType);
+  }
+
   @Override
   public RecordReader createDBRecordReader(DBInputSplit split, Configuration conf) throws IOException {
     final RecordReader dbRecordReader = super.createDBRecordReader(split, conf);

database-commons/src/main/java/io/cdap/plugin/db/source/SafeBigDecimalSplitter.java

@@ -0,0 +1,55 @@
+/*
+ * Copyright © 2025 Cask Data, Inc.
+ *
+ * Licensed 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 io.cdap.plugin.db.source;
+
+import org.apache.hadoop.mapreduce.lib.db.BigDecimalSplitter;
+import java.math.BigDecimal;
+import java.math.RoundingMode;
+
+/**
+ * Safe implementation of {@link BigDecimalSplitter} to ensure precise division of BigDecimal values while calculating
+ * split points for NUMERIC and DECIMAL types.
+ *
+ * <p>Problem: The default {@link BigDecimalSplitter} implementation may return 0 when the numerator is smaller than the
+ * denominator (e.g., 1 / 4 = 0), due to the lack of a defined scale for division. Since the result (0) is smaller than
+ * {@link BigDecimalSplitter#MIN_INCREMENT} (i.e. {@code 10000 * Double.MIN_VALUE}), the split size defaults to
+ * {@code MIN_INCREMENT}, leading to an excessive number of splits (~10M) and potential OOM errors.</p>
+ *
+ * <p>Fix: This implementation derives scale from column metadata, adds a buffer of 5 decimal places, and uses
+ * {@link RoundingMode#HALF_UP} as the rounding mode.</p
+ *
+ * <p>Note: This class is used by {@link DataDrivenETLDBInputFormat}.</p>
+ */
+public class SafeBigDecimalSplitter extends BigDecimalSplitter {
+
+  /* An additional buffer of +5 digits is applied to preserve accuracy during division. */
+  public static final int SCALE_BUFFER = 5;
+  /**
+   * Performs safe division with correct scale handling.
+   *
+   * @param numerator   the dividend (BigDecimal)
+   * @param denominator the divisor (BigDecimal)
+   * @return quotient with derived scale
+   * @throws ArithmeticException if denominator is zero
+   */
+  @Override
+  protected BigDecimal tryDivide(BigDecimal numerator, BigDecimal denominator) {
+    // Determine the required scale for the division and add a buffer to ensure accuracy
+    int effectiveScale = Math.max(numerator.scale(), denominator.scale()) + SCALE_BUFFER;
+    return numerator.divide(denominator, effectiveScale, RoundingMode.HALF_UP);
+  }
+}

database-commons/src/test/java/io/cdap/plugin/db/source/SafeBigDecimalSplitterTest.java

@@ -0,0 +1,98 @@
+/*
+ * Copyright © 2025 Cask Data, Inc.
+ *
+ * Licensed 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 io.cdap.plugin.db.source;
+
+import org.apache.hadoop.conf.Configuration;
+import org.apache.hadoop.mapreduce.InputSplit;
+import org.apache.hadoop.mapreduce.lib.db.BigDecimalSplitter;
+import org.junit.Test;
+
+import java.math.BigDecimal;
+import java.sql.ResultSet;
+import java.sql.SQLException;
+import java.util.List;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertThrows;
+import static org.junit.Assert.assertTrue;
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.when;
+
+/**
+ * Test class for {@link SafeBigDecimalSplitter}
+ */
+public class SafeBigDecimalSplitterTest {
+  private final SafeBigDecimalSplitter splitter = new SafeBigDecimalSplitter();
+
+  @Test
+  public void testSmallRangeDivision() {
+    BigDecimal result = splitter.tryDivide(BigDecimal.ONE, new BigDecimal("4"));
+    assertEquals(new BigDecimal("0.25000"), result);
+  }
+
+  @Test
+  public void testLargePrecision() {
+    BigDecimal numerator = new BigDecimal("1.0000000000000000001");
+    BigDecimal denominator = new BigDecimal("3");
+    BigDecimal result = splitter.tryDivide(numerator, denominator);
+    assertTrue(result.compareTo(BigDecimal.ZERO) > 0);
+  }
+
+  @Test
+  public void testDivisionByZero() {
+    assertThrows(ArithmeticException.class, () ->
+      splitter.tryDivide(BigDecimal.ONE, BigDecimal.ZERO));
+  }
+
+  @Test
+  public void testDivisionWithZeroNumerator() {
+    // when minVal == maxVal
+    BigDecimal result = splitter.tryDivide(BigDecimal.ZERO, BigDecimal.ONE);
+    assertEquals(0, result.compareTo(BigDecimal.ZERO));
+  }
+
+  @Test
+  public void testSplits() throws SQLException {
+    BigDecimal minVal = BigDecimal.valueOf(1);
+    BigDecimal maxVal = BigDecimal.valueOf(2);
+    int numSplits = 4;
+    ResultSet resultSet = mock(ResultSet.class);
+    Configuration conf = mock(Configuration.class);
+    when(conf.getInt("mapreduce.job.maps", 1)).thenReturn(numSplits);
+    when(resultSet.getBigDecimal(1)).thenReturn(minVal);
+    when(resultSet.getBigDecimal(2)).thenReturn(maxVal);
+    BigDecimalSplitter bigDecimalSplitter = new SafeBigDecimalSplitter();
+    List<InputSplit> actualSplits = bigDecimalSplitter.split(conf, resultSet, "id");
+    assertEquals(numSplits, actualSplits.size());
+  }
+
+  @Test
+  public void testSplitsWithMinValueEqualToMaxValue() throws SQLException {
+    // when minVal == maxVal
+    BigDecimal minVal = BigDecimal.valueOf(1);
+    BigDecimal maxVal = BigDecimal.valueOf(1);
+    int numSplits = 1;
+    ResultSet resultSet = mock(ResultSet.class);
+    Configuration conf = mock(Configuration.class);
+    when(conf.getInt("mapreduce.job.maps", 1)).thenReturn(numSplits);
+    when(resultSet.getBigDecimal(1)).thenReturn(minVal);
+    when(resultSet.getBigDecimal(2)).thenReturn(maxVal);
+    BigDecimalSplitter bigDecimalSplitter = new SafeBigDecimalSplitter();
+    List<InputSplit> actualSplits = bigDecimalSplitter.split(conf, resultSet, "id");
+    assertEquals(numSplits, actualSplits.size());
+  }
+}

pom.xml

@@ -78,7 +78,7 @@
     <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
     <!-- version properties -->
     <cdap.version>6.11.0</cdap.version>
-    <cdap.plugin.version>2.13.1-SNAPSHOT</cdap.plugin.version>
+    <cdap.plugin.version>2.13.1</cdap.plugin.version>
     <guava.version>13.0.1</guava.version>
     <hadoop.version>3.3.6</hadoop.version>
     <hsql.version>2.2.4</hsql.version>

postgresql-plugin/src/e2e-test/resources/errorMessage.properties

@@ -16,7 +16,7 @@ errorMessageBlankPassword=SQL error while getting query schema: The server reque
 errorMessageInvalidPassword=SQL error while getting query schema: FATAL: password authentication failed for user
 errorMessageInvalidSourceHost=SQL error while getting query schema: The connection attempt failed.
 errorMessageInvalidTableName=Table 'table' does not exist. Ensure table '"table"' is set correctly and that the
-errorMessageInvalidSinkDatabase=Error encountered while configuring the stage: 'SQL Error occurred, sqlState: '08004', errorCode: '0', errorMessage: SQL Exception occurred: [Message='The server requested SCRAM-based authentication
+errorMessageInvalidSinkDatabase=Error encountered while configuring the stage: 'SQL Error occurred, sqlState: '3D000', errorCode: '0', errorMessage: SQL Exception occurred
 errorMessageInvalidHost=Error encountered while configuring the stage: 'SQL Error occurred, sqlState: '08001', errorCode: '0', errorMessage: SQL Exception occurred: [Message='The connection attempt failed.', SQLState='08001', ErrorCode='0'].'
 errorLogsMessageInvalidBoundingQuery=Spark program 'phase-1' failed with error: Stage 'PostgreSQL' encountered : \
   java.io.IOException: The column index is out of range: 1, number of columns: 0.. Please check the system logs for more details.