[GitHub] [hudi] vinothchandar commented on a change in pull request #2915: [HUDI-251] Adds JDBC source support for DeltaStreamer

[GitBox <gi...@apache.org>]

vinothchandar commented on a change in pull request #2915:
URL: https://github.com/apache/hudi/pull/2915#discussion_r627987063



##########
File path: hudi-utilities/src/main/java/org/apache/hudi/utilities/SqlQueryBuilder.java
##########
@@ -0,0 +1,160 @@
+/*
+ * 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.hudi.utilities;
+
+import org.apache.hudi.common.util.StringUtils;
+
+/**
+ * Fluent SQL query builder.

Review comment:
       is Fluent an external library? are you reusing code from somewhere? if so, we need to attribute this. 

##########
File path: hudi-utilities/src/main/java/org/apache/hudi/utilities/SqlQueryBuilder.java
##########
@@ -0,0 +1,160 @@
+/*
+ * 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.hudi.utilities;
+
+import org.apache.hudi.common.util.StringUtils;
+
+/**
+ * Fluent SQL query builder.
+ * Current support for: SELECT, FROM, JOIN, ON, WHERE, ORDER BY, LIMIT clauses.
+ */
+public class SqlQueryBuilder {
+
+  private StringBuilder sqlBuilder;
+
+  private SqlQueryBuilder(StringBuilder sqlBuilder) {
+    this.sqlBuilder = sqlBuilder;
+  }
+
+  /**
+   * Creates a SELECT query.
+   *
+   * @param columns The column names to select.
+   * @return The new {@link SqlQueryBuilder} instance.
+   */
+  public static SqlQueryBuilder select(String... columns) {
+    if (columns == null || columns.length == 0) {
+      throw new IllegalArgumentException();
+    }
+
+    StringBuilder sqlBuilder = new StringBuilder();
+    sqlBuilder.append("select ");
+    sqlBuilder.append(String.join(", ", columns));
+
+    return new SqlQueryBuilder(sqlBuilder);
+  }
+
+  /**
+   * Appends a FROM clause to a query.
+   *
+   * @param tables The table names to select from.
+   * @return The {@link SqlQueryBuilder} instance.
+   */
+  public SqlQueryBuilder from(String... tables) {
+    if (tables == null || tables.length == 0) {
+      throw new IllegalArgumentException();
+    }
+
+    sqlBuilder.append(" from ");
+    sqlBuilder.append(String.join(", ", tables));
+
+    return this;
+  }
+
+  /**
+   * Appends a JOIN clause to a query.
+   *
+   * @param table The table to join with.
+   * @return The {@link SqlQueryBuilder} instance.
+   */
+  public SqlQueryBuilder join(String table) {
+    if (StringUtils.isNullOrEmpty(table)) {
+      throw new IllegalArgumentException();
+    }
+
+    sqlBuilder.append(" join ");
+    sqlBuilder.append(table);
+

Review comment:
       nit: remove redundant newline? (here and everywhere else?)

##########
File path: hudi-utilities/src/main/java/org/apache/hudi/utilities/SqlQueryBuilder.java
##########
@@ -0,0 +1,160 @@
+/*
+ * 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.hudi.utilities;
+
+import org.apache.hudi.common.util.StringUtils;
+
+/**
+ * Fluent SQL query builder.
+ * Current support for: SELECT, FROM, JOIN, ON, WHERE, ORDER BY, LIMIT clauses.
+ */
+public class SqlQueryBuilder {
+
+  private StringBuilder sqlBuilder;
+
+  private SqlQueryBuilder(StringBuilder sqlBuilder) {
+    this.sqlBuilder = sqlBuilder;
+  }
+
+  /**
+   * Creates a SELECT query.
+   *
+   * @param columns The column names to select.
+   * @return The new {@link SqlQueryBuilder} instance.
+   */
+  public static SqlQueryBuilder select(String... columns) {
+    if (columns == null || columns.length == 0) {
+      throw new IllegalArgumentException();
+    }
+
+    StringBuilder sqlBuilder = new StringBuilder();
+    sqlBuilder.append("select ");
+    sqlBuilder.append(String.join(", ", columns));
+
+    return new SqlQueryBuilder(sqlBuilder);
+  }
+
+  /**
+   * Appends a FROM clause to a query.
+   *
+   * @param tables The table names to select from.
+   * @return The {@link SqlQueryBuilder} instance.
+   */
+  public SqlQueryBuilder from(String... tables) {
+    if (tables == null || tables.length == 0) {
+      throw new IllegalArgumentException();
+    }
+
+    sqlBuilder.append(" from ");
+    sqlBuilder.append(String.join(", ", tables));

Review comment:
       for now, we are keeping it simple to fetching a single table based on a some checkpoint column. This was discussed in the RFC, to keep this scoped down and have something working end-to-end. 

##########
File path: hudi-utilities/src/main/java/org/apache/hudi/utilities/sources/JdbcSource.java
##########
@@ -0,0 +1,326 @@
+/*
+ * 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.hudi.utilities.sources;
+
+import org.apache.hudi.DataSourceUtils;
+import org.apache.hudi.common.config.TypedProperties;
+import org.apache.hudi.common.util.Option;
+import org.apache.hudi.common.util.StringUtils;
+import org.apache.hudi.common.util.collection.Pair;
+import org.apache.hudi.exception.HoodieException;
+import org.apache.hudi.utilities.SqlQueryBuilder;
+import org.apache.hudi.utilities.schema.SchemaProvider;
+
+import org.apache.hadoop.fs.FSDataInputStream;
+import org.apache.hadoop.fs.FileSystem;
+import org.apache.hadoop.fs.Path;
+import org.apache.hadoop.io.IOUtils;
+import org.apache.log4j.LogManager;
+import org.apache.log4j.Logger;
+import org.apache.spark.api.java.JavaSparkContext;
+import org.apache.spark.sql.Column;
+import org.apache.spark.sql.DataFrameReader;
+import org.apache.spark.sql.Dataset;
+import org.apache.spark.sql.Row;
+import org.apache.spark.sql.SparkSession;
+import org.apache.spark.sql.functions;
+import org.apache.spark.sql.types.DataTypes;
+import org.apache.spark.storage.StorageLevel;
+import org.jetbrains.annotations.NotNull;
+
+import java.net.URI;
+import java.util.Arrays;
+import java.util.Collections;
+import java.util.List;
+import java.util.Set;
+
+/**
+ * Reads data from RDBMS data sources.
+ */
+
+public class JdbcSource extends RowSource {
+
+  private static final Logger LOG = LogManager.getLogger(JdbcSource.class);
+  private static final List<String> DB_LIMIT_CLAUSE = Arrays.asList("mysql", "postgresql", "h2");
+  private static final String URI_JDBC_PREFIX = "jdbc:";
+
+  public JdbcSource(TypedProperties props, JavaSparkContext sparkContext, SparkSession sparkSession,
+                    SchemaProvider schemaProvider) {
+    super(props, sparkContext, sparkSession, schemaProvider);
+  }
+
+  /**
+   * Validates all user properties and prepares the {@link DataFrameReader} to read from RDBMS.
+   *
+   * @param session    The {@link SparkSession}.
+   * @param properties The JDBC connection properties and data source options.
+   * @return The {@link DataFrameReader} to read from RDBMS
+   * @throws HoodieException
+   */
+  private static DataFrameReader validatePropsAndGetDataFrameReader(final SparkSession session,
+                                                                    final TypedProperties properties)
+      throws HoodieException {
+    DataFrameReader dataFrameReader;
+    FSDataInputStream passwordFileStream = null;
+    try {
+      dataFrameReader = session.read().format("jdbc");
+      dataFrameReader = dataFrameReader.option(Config.URL_PROP, properties.getString(Config.URL));
+      dataFrameReader = dataFrameReader.option(Config.USER_PROP, properties.getString(Config.USER));
+      dataFrameReader = dataFrameReader.option(Config.DRIVER_PROP, properties.getString(Config.DRIVER_CLASS));
+      dataFrameReader = dataFrameReader
+          .option(Config.RDBMS_TABLE_PROP, properties.getString(Config.RDBMS_TABLE_NAME));
+
+      if (properties.containsKey(Config.PASSWORD)) {
+        LOG.info("Reading JDBC password from properties file....");
+        dataFrameReader = dataFrameReader.option(Config.PASSWORD_PROP, properties.getString(Config.PASSWORD));
+      } else if (properties.containsKey(Config.PASSWORD_FILE)
+          && !StringUtils.isNullOrEmpty(properties.getString(Config.PASSWORD_FILE))) {
+        LOG.info(String.format("Reading JDBC password from password file %s", properties.getString(Config.PASSWORD_FILE)));
+        FileSystem fileSystem = FileSystem.get(session.sparkContext().hadoopConfiguration());
+        passwordFileStream = fileSystem.open(new Path(properties.getString(Config.PASSWORD_FILE)));
+        byte[] bytes = new byte[passwordFileStream.available()];
+        passwordFileStream.read(bytes);
+        dataFrameReader = dataFrameReader.option(Config.PASSWORD_PROP, new String(bytes));
+      } else {
+        throw new IllegalArgumentException(String.format("JDBCSource needs either a %s or %s to connect to RDBMS "
+            + "datasource", Config.PASSWORD_FILE, Config.PASSWORD));
+      }
+
+      addExtraJdbcOptions(properties, dataFrameReader);
+
+      if (properties.getBoolean(Config.IS_INCREMENTAL)) {
+        DataSourceUtils.checkRequiredProperties(properties, Collections.singletonList(Config.INCREMENTAL_COLUMN));
+      }
+      return dataFrameReader;
+    } catch (Exception e) {
+      throw new HoodieException(e);
+    } finally {
+      IOUtils.closeStream(passwordFileStream);
+    }
+  }
+
+  /**
+   * Accepts spark JDBC options from the user in terms of EXTRA_OPTIONS adds them to {@link DataFrameReader} Example: In
+   * a normal spark code you would do something like: session.read.format('jdbc') .option(fetchSize,1000)
+   * .option(timestampFormat,"yyyy-mm-dd hh:mm:ss")
+   * <p>
+   * The way to pass these properties to HUDI is through the config file. Any property starting with
+   * hoodie.datasource.jdbc.extra.options. will be added.
+   * <p>
+   * Example: hoodie.datasource.jdbc.extra.options.fetchSize=100
+   * hoodie.datasource.jdbc.extra.options.upperBound=1
+   * hoodie.datasource.jdbc.extra.options.lowerBound=100
+   *
+   * @param properties      The JDBC connection properties and data source options.
+   * @param dataFrameReader The {@link DataFrameReader} to which data source options will be added.
+   */
+  private static void addExtraJdbcOptions(TypedProperties properties, DataFrameReader dataFrameReader) {
+    Set<Object> objects = properties.keySet();
+    for (Object property : objects) {
+      String prop = (String) property;
+      if (prop.startsWith(Config.EXTRA_OPTIONS)) {
+        String key = String.join("", prop.split(Config.EXTRA_OPTIONS));
+        String value = properties.getString(prop);
+        if (!StringUtils.isNullOrEmpty(value)) {
+          LOG.info(String.format("Adding %s -> %s to jdbc options", key, value));
+          dataFrameReader.option(key, value);
+        }
+      }
+    }
+  }
+
+  @Override
+  protected Pair<Option<Dataset<Row>>, String> fetchNextBatch(Option<String> lastCkptStr, long sourceLimit) {
+    try {
+      DataSourceUtils.checkRequiredProperties(props, Arrays.asList(Config.URL, Config.DRIVER_CLASS, Config.USER, Config.RDBMS_TABLE_NAME, Config.IS_INCREMENTAL));
+      return fetch(lastCkptStr, sourceLimit);
+    } catch (Exception e) {
+      LOG.error("Exception while running JDBCSource ", e);

Review comment:
       +1 to throw an exception. 

##########
File path: hudi-utilities/src/main/java/org/apache/hudi/utilities/sources/JdbcSource.java
##########
@@ -0,0 +1,326 @@
+/*
+ * 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.hudi.utilities.sources;
+
+import org.apache.hudi.DataSourceUtils;
+import org.apache.hudi.common.config.TypedProperties;
+import org.apache.hudi.common.util.Option;
+import org.apache.hudi.common.util.StringUtils;
+import org.apache.hudi.common.util.collection.Pair;
+import org.apache.hudi.exception.HoodieException;
+import org.apache.hudi.utilities.SqlQueryBuilder;
+import org.apache.hudi.utilities.schema.SchemaProvider;
+
+import org.apache.hadoop.fs.FSDataInputStream;
+import org.apache.hadoop.fs.FileSystem;
+import org.apache.hadoop.fs.Path;
+import org.apache.hadoop.io.IOUtils;
+import org.apache.log4j.LogManager;
+import org.apache.log4j.Logger;
+import org.apache.spark.api.java.JavaSparkContext;
+import org.apache.spark.sql.Column;
+import org.apache.spark.sql.DataFrameReader;
+import org.apache.spark.sql.Dataset;
+import org.apache.spark.sql.Row;
+import org.apache.spark.sql.SparkSession;
+import org.apache.spark.sql.functions;
+import org.apache.spark.sql.types.DataTypes;
+import org.apache.spark.storage.StorageLevel;
+import org.jetbrains.annotations.NotNull;
+
+import java.net.URI;
+import java.util.Arrays;
+import java.util.Collections;
+import java.util.List;
+import java.util.Set;
+
+/**
+ * Reads data from RDBMS data sources.
+ */
+
+public class JdbcSource extends RowSource {
+
+  private static final Logger LOG = LogManager.getLogger(JdbcSource.class);
+  private static final List<String> DB_LIMIT_CLAUSE = Arrays.asList("mysql", "postgresql", "h2");
+  private static final String URI_JDBC_PREFIX = "jdbc:";
+
+  public JdbcSource(TypedProperties props, JavaSparkContext sparkContext, SparkSession sparkSession,
+                    SchemaProvider schemaProvider) {
+    super(props, sparkContext, sparkSession, schemaProvider);
+  }
+
+  /**
+   * Validates all user properties and prepares the {@link DataFrameReader} to read from RDBMS.
+   *
+   * @param session    The {@link SparkSession}.
+   * @param properties The JDBC connection properties and data source options.
+   * @return The {@link DataFrameReader} to read from RDBMS
+   * @throws HoodieException
+   */
+  private static DataFrameReader validatePropsAndGetDataFrameReader(final SparkSession session,
+                                                                    final TypedProperties properties)
+      throws HoodieException {
+    DataFrameReader dataFrameReader;
+    FSDataInputStream passwordFileStream = null;
+    try {
+      dataFrameReader = session.read().format("jdbc");
+      dataFrameReader = dataFrameReader.option(Config.URL_PROP, properties.getString(Config.URL));
+      dataFrameReader = dataFrameReader.option(Config.USER_PROP, properties.getString(Config.USER));
+      dataFrameReader = dataFrameReader.option(Config.DRIVER_PROP, properties.getString(Config.DRIVER_CLASS));
+      dataFrameReader = dataFrameReader
+          .option(Config.RDBMS_TABLE_PROP, properties.getString(Config.RDBMS_TABLE_NAME));
+
+      if (properties.containsKey(Config.PASSWORD)) {
+        LOG.info("Reading JDBC password from properties file....");
+        dataFrameReader = dataFrameReader.option(Config.PASSWORD_PROP, properties.getString(Config.PASSWORD));
+      } else if (properties.containsKey(Config.PASSWORD_FILE)
+          && !StringUtils.isNullOrEmpty(properties.getString(Config.PASSWORD_FILE))) {
+        LOG.info(String.format("Reading JDBC password from password file %s", properties.getString(Config.PASSWORD_FILE)));
+        FileSystem fileSystem = FileSystem.get(session.sparkContext().hadoopConfiguration());
+        passwordFileStream = fileSystem.open(new Path(properties.getString(Config.PASSWORD_FILE)));
+        byte[] bytes = new byte[passwordFileStream.available()];
+        passwordFileStream.read(bytes);
+        dataFrameReader = dataFrameReader.option(Config.PASSWORD_PROP, new String(bytes));
+      } else {
+        throw new IllegalArgumentException(String.format("JDBCSource needs either a %s or %s to connect to RDBMS "
+            + "datasource", Config.PASSWORD_FILE, Config.PASSWORD));
+      }
+
+      addExtraJdbcOptions(properties, dataFrameReader);
+
+      if (properties.getBoolean(Config.IS_INCREMENTAL)) {
+        DataSourceUtils.checkRequiredProperties(properties, Collections.singletonList(Config.INCREMENTAL_COLUMN));
+      }
+      return dataFrameReader;
+    } catch (Exception e) {
+      throw new HoodieException(e);
+    } finally {
+      IOUtils.closeStream(passwordFileStream);
+    }
+  }
+
+  /**
+   * Accepts spark JDBC options from the user in terms of EXTRA_OPTIONS adds them to {@link DataFrameReader} Example: In
+   * a normal spark code you would do something like: session.read.format('jdbc') .option(fetchSize,1000)
+   * .option(timestampFormat,"yyyy-mm-dd hh:mm:ss")
+   * <p>
+   * The way to pass these properties to HUDI is through the config file. Any property starting with
+   * hoodie.datasource.jdbc.extra.options. will be added.
+   * <p>
+   * Example: hoodie.datasource.jdbc.extra.options.fetchSize=100
+   * hoodie.datasource.jdbc.extra.options.upperBound=1
+   * hoodie.datasource.jdbc.extra.options.lowerBound=100
+   *
+   * @param properties      The JDBC connection properties and data source options.
+   * @param dataFrameReader The {@link DataFrameReader} to which data source options will be added.
+   */
+  private static void addExtraJdbcOptions(TypedProperties properties, DataFrameReader dataFrameReader) {
+    Set<Object> objects = properties.keySet();
+    for (Object property : objects) {
+      String prop = (String) property;
+      if (prop.startsWith(Config.EXTRA_OPTIONS)) {
+        String key = String.join("", prop.split(Config.EXTRA_OPTIONS));
+        String value = properties.getString(prop);
+        if (!StringUtils.isNullOrEmpty(value)) {
+          LOG.info(String.format("Adding %s -> %s to jdbc options", key, value));
+          dataFrameReader.option(key, value);
+        }
+      }
+    }
+  }
+
+  @Override
+  protected Pair<Option<Dataset<Row>>, String> fetchNextBatch(Option<String> lastCkptStr, long sourceLimit) {
+    try {
+      DataSourceUtils.checkRequiredProperties(props, Arrays.asList(Config.URL, Config.DRIVER_CLASS, Config.USER, Config.RDBMS_TABLE_NAME, Config.IS_INCREMENTAL));
+      return fetch(lastCkptStr, sourceLimit);
+    } catch (Exception e) {
+      LOG.error("Exception while running JDBCSource ", e);
+      return Pair.of(Option.empty(), null);
+    }
+  }
+
+  /**
+   * Decide to do a full RDBMS table scan or an incremental scan based on the lastCkptStr. If previous checkpoint
+   * value exists then we do an incremental scan with a PPD query or else we do a full scan. In certain cases where the
+   * incremental query fails, we fallback to a full scan.
+   *
+   * @param lastCkptStr Last checkpoint.
+   * @return The pair of {@link Dataset} and current checkpoint.
+   */
+  @NotNull
+  private Pair<Option<Dataset<Row>>, String> fetch(Option<String> lastCkptStr, long sourceLimit) {
+    Dataset<Row> dataset;
+    if (lastCkptStr.isPresent() && !StringUtils.isNullOrEmpty(lastCkptStr.get())) {
+      dataset = incrementalFetch(lastCkptStr, sourceLimit);
+    } else {
+      LOG.info("No checkpoint references found. Doing a full rdbms table fetch");
+      dataset = fullFetch();
+    }
+
+    if (props.containsKey(Config.STORAGE_LEVEL) && !StringUtils.isNullOrEmpty(props.getString(Config.STORAGE_LEVEL))) {

Review comment:
       is there a way to simplify these checks and fetch a default value for the storage level? 

##########
File path: hudi-utilities/src/main/java/org/apache/hudi/utilities/sources/JdbcSource.java
##########
@@ -0,0 +1,326 @@
+/*
+ * 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.hudi.utilities.sources;
+
+import org.apache.hudi.DataSourceUtils;
+import org.apache.hudi.common.config.TypedProperties;
+import org.apache.hudi.common.util.Option;
+import org.apache.hudi.common.util.StringUtils;
+import org.apache.hudi.common.util.collection.Pair;
+import org.apache.hudi.exception.HoodieException;
+import org.apache.hudi.utilities.SqlQueryBuilder;
+import org.apache.hudi.utilities.schema.SchemaProvider;
+
+import org.apache.hadoop.fs.FSDataInputStream;
+import org.apache.hadoop.fs.FileSystem;
+import org.apache.hadoop.fs.Path;
+import org.apache.hadoop.io.IOUtils;
+import org.apache.log4j.LogManager;
+import org.apache.log4j.Logger;
+import org.apache.spark.api.java.JavaSparkContext;
+import org.apache.spark.sql.Column;
+import org.apache.spark.sql.DataFrameReader;
+import org.apache.spark.sql.Dataset;
+import org.apache.spark.sql.Row;
+import org.apache.spark.sql.SparkSession;
+import org.apache.spark.sql.functions;
+import org.apache.spark.sql.types.DataTypes;
+import org.apache.spark.storage.StorageLevel;
+import org.jetbrains.annotations.NotNull;
+
+import java.net.URI;
+import java.util.Arrays;
+import java.util.Collections;
+import java.util.List;
+import java.util.Set;
+
+/**
+ * Reads data from RDBMS data sources.
+ */
+
+public class JdbcSource extends RowSource {
+
+  private static final Logger LOG = LogManager.getLogger(JdbcSource.class);
+  private static final List<String> DB_LIMIT_CLAUSE = Arrays.asList("mysql", "postgresql", "h2");
+  private static final String URI_JDBC_PREFIX = "jdbc:";
+
+  public JdbcSource(TypedProperties props, JavaSparkContext sparkContext, SparkSession sparkSession,
+                    SchemaProvider schemaProvider) {
+    super(props, sparkContext, sparkSession, schemaProvider);
+  }
+
+  /**
+   * Validates all user properties and prepares the {@link DataFrameReader} to read from RDBMS.
+   *
+   * @param session    The {@link SparkSession}.
+   * @param properties The JDBC connection properties and data source options.
+   * @return The {@link DataFrameReader} to read from RDBMS
+   * @throws HoodieException
+   */
+  private static DataFrameReader validatePropsAndGetDataFrameReader(final SparkSession session,
+                                                                    final TypedProperties properties)
+      throws HoodieException {
+    DataFrameReader dataFrameReader;
+    FSDataInputStream passwordFileStream = null;
+    try {
+      dataFrameReader = session.read().format("jdbc");
+      dataFrameReader = dataFrameReader.option(Config.URL_PROP, properties.getString(Config.URL));
+      dataFrameReader = dataFrameReader.option(Config.USER_PROP, properties.getString(Config.USER));
+      dataFrameReader = dataFrameReader.option(Config.DRIVER_PROP, properties.getString(Config.DRIVER_CLASS));
+      dataFrameReader = dataFrameReader
+          .option(Config.RDBMS_TABLE_PROP, properties.getString(Config.RDBMS_TABLE_NAME));
+
+      if (properties.containsKey(Config.PASSWORD)) {
+        LOG.info("Reading JDBC password from properties file....");
+        dataFrameReader = dataFrameReader.option(Config.PASSWORD_PROP, properties.getString(Config.PASSWORD));
+      } else if (properties.containsKey(Config.PASSWORD_FILE)
+          && !StringUtils.isNullOrEmpty(properties.getString(Config.PASSWORD_FILE))) {
+        LOG.info(String.format("Reading JDBC password from password file %s", properties.getString(Config.PASSWORD_FILE)));
+        FileSystem fileSystem = FileSystem.get(session.sparkContext().hadoopConfiguration());
+        passwordFileStream = fileSystem.open(new Path(properties.getString(Config.PASSWORD_FILE)));
+        byte[] bytes = new byte[passwordFileStream.available()];
+        passwordFileStream.read(bytes);
+        dataFrameReader = dataFrameReader.option(Config.PASSWORD_PROP, new String(bytes));
+      } else {
+        throw new IllegalArgumentException(String.format("JDBCSource needs either a %s or %s to connect to RDBMS "
+            + "datasource", Config.PASSWORD_FILE, Config.PASSWORD));
+      }
+
+      addExtraJdbcOptions(properties, dataFrameReader);
+
+      if (properties.getBoolean(Config.IS_INCREMENTAL)) {
+        DataSourceUtils.checkRequiredProperties(properties, Collections.singletonList(Config.INCREMENTAL_COLUMN));
+      }
+      return dataFrameReader;
+    } catch (Exception e) {
+      throw new HoodieException(e);
+    } finally {
+      IOUtils.closeStream(passwordFileStream);
+    }
+  }
+
+  /**
+   * Accepts spark JDBC options from the user in terms of EXTRA_OPTIONS adds them to {@link DataFrameReader} Example: In
+   * a normal spark code you would do something like: session.read.format('jdbc') .option(fetchSize,1000)
+   * .option(timestampFormat,"yyyy-mm-dd hh:mm:ss")
+   * <p>
+   * The way to pass these properties to HUDI is through the config file. Any property starting with
+   * hoodie.datasource.jdbc.extra.options. will be added.
+   * <p>
+   * Example: hoodie.datasource.jdbc.extra.options.fetchSize=100
+   * hoodie.datasource.jdbc.extra.options.upperBound=1
+   * hoodie.datasource.jdbc.extra.options.lowerBound=100
+   *
+   * @param properties      The JDBC connection properties and data source options.
+   * @param dataFrameReader The {@link DataFrameReader} to which data source options will be added.
+   */
+  private static void addExtraJdbcOptions(TypedProperties properties, DataFrameReader dataFrameReader) {
+    Set<Object> objects = properties.keySet();
+    for (Object property : objects) {
+      String prop = (String) property;
+      if (prop.startsWith(Config.EXTRA_OPTIONS)) {
+        String key = String.join("", prop.split(Config.EXTRA_OPTIONS));
+        String value = properties.getString(prop);
+        if (!StringUtils.isNullOrEmpty(value)) {
+          LOG.info(String.format("Adding %s -> %s to jdbc options", key, value));
+          dataFrameReader.option(key, value);
+        }
+      }
+    }
+  }
+
+  @Override
+  protected Pair<Option<Dataset<Row>>, String> fetchNextBatch(Option<String> lastCkptStr, long sourceLimit) {
+    try {
+      DataSourceUtils.checkRequiredProperties(props, Arrays.asList(Config.URL, Config.DRIVER_CLASS, Config.USER, Config.RDBMS_TABLE_NAME, Config.IS_INCREMENTAL));
+      return fetch(lastCkptStr, sourceLimit);
+    } catch (Exception e) {
+      LOG.error("Exception while running JDBCSource ", e);
+      return Pair.of(Option.empty(), null);
+    }
+  }
+
+  /**
+   * Decide to do a full RDBMS table scan or an incremental scan based on the lastCkptStr. If previous checkpoint
+   * value exists then we do an incremental scan with a PPD query or else we do a full scan. In certain cases where the
+   * incremental query fails, we fallback to a full scan.
+   *
+   * @param lastCkptStr Last checkpoint.
+   * @return The pair of {@link Dataset} and current checkpoint.
+   */
+  @NotNull
+  private Pair<Option<Dataset<Row>>, String> fetch(Option<String> lastCkptStr, long sourceLimit) {
+    Dataset<Row> dataset;
+    if (lastCkptStr.isPresent() && !StringUtils.isNullOrEmpty(lastCkptStr.get())) {
+      dataset = incrementalFetch(lastCkptStr, sourceLimit);
+    } else {
+      LOG.info("No checkpoint references found. Doing a full rdbms table fetch");

Review comment:
       this could remain `info` IMO. its not really a unexpected scenario.

##########
File path: hudi-utilities/src/main/java/org/apache/hudi/utilities/sources/JdbcSource.java
##########
@@ -0,0 +1,326 @@
+/*
+ * 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.hudi.utilities.sources;
+
+import org.apache.hudi.DataSourceUtils;
+import org.apache.hudi.common.config.TypedProperties;
+import org.apache.hudi.common.util.Option;
+import org.apache.hudi.common.util.StringUtils;
+import org.apache.hudi.common.util.collection.Pair;
+import org.apache.hudi.exception.HoodieException;
+import org.apache.hudi.utilities.SqlQueryBuilder;
+import org.apache.hudi.utilities.schema.SchemaProvider;
+
+import org.apache.hadoop.fs.FSDataInputStream;
+import org.apache.hadoop.fs.FileSystem;
+import org.apache.hadoop.fs.Path;
+import org.apache.hadoop.io.IOUtils;
+import org.apache.log4j.LogManager;
+import org.apache.log4j.Logger;
+import org.apache.spark.api.java.JavaSparkContext;
+import org.apache.spark.sql.Column;
+import org.apache.spark.sql.DataFrameReader;
+import org.apache.spark.sql.Dataset;
+import org.apache.spark.sql.Row;
+import org.apache.spark.sql.SparkSession;
+import org.apache.spark.sql.functions;
+import org.apache.spark.sql.types.DataTypes;
+import org.apache.spark.storage.StorageLevel;
+import org.jetbrains.annotations.NotNull;

Review comment:
       is this import needed ? I don't think we depend on jetbrains anywhere or am I wrong?

##########
File path: hudi-utilities/src/main/java/org/apache/hudi/utilities/sources/JdbcSource.java
##########
@@ -0,0 +1,326 @@
+/*
+ * 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.hudi.utilities.sources;
+
+import org.apache.hudi.DataSourceUtils;
+import org.apache.hudi.common.config.TypedProperties;
+import org.apache.hudi.common.util.Option;
+import org.apache.hudi.common.util.StringUtils;
+import org.apache.hudi.common.util.collection.Pair;
+import org.apache.hudi.exception.HoodieException;
+import org.apache.hudi.utilities.SqlQueryBuilder;
+import org.apache.hudi.utilities.schema.SchemaProvider;
+
+import org.apache.hadoop.fs.FSDataInputStream;
+import org.apache.hadoop.fs.FileSystem;
+import org.apache.hadoop.fs.Path;
+import org.apache.hadoop.io.IOUtils;
+import org.apache.log4j.LogManager;
+import org.apache.log4j.Logger;
+import org.apache.spark.api.java.JavaSparkContext;
+import org.apache.spark.sql.Column;
+import org.apache.spark.sql.DataFrameReader;
+import org.apache.spark.sql.Dataset;
+import org.apache.spark.sql.Row;
+import org.apache.spark.sql.SparkSession;
+import org.apache.spark.sql.functions;
+import org.apache.spark.sql.types.DataTypes;
+import org.apache.spark.storage.StorageLevel;
+import org.jetbrains.annotations.NotNull;
+
+import java.net.URI;
+import java.util.Arrays;
+import java.util.Collections;
+import java.util.List;
+import java.util.Set;
+
+/**
+ * Reads data from RDBMS data sources.
+ */
+
+public class JdbcSource extends RowSource {
+
+  private static final Logger LOG = LogManager.getLogger(JdbcSource.class);
+  private static final List<String> DB_LIMIT_CLAUSE = Arrays.asList("mysql", "postgresql", "h2");
+  private static final String URI_JDBC_PREFIX = "jdbc:";
+
+  public JdbcSource(TypedProperties props, JavaSparkContext sparkContext, SparkSession sparkSession,
+                    SchemaProvider schemaProvider) {
+    super(props, sparkContext, sparkSession, schemaProvider);
+  }
+
+  /**
+   * Validates all user properties and prepares the {@link DataFrameReader} to read from RDBMS.
+   *
+   * @param session    The {@link SparkSession}.
+   * @param properties The JDBC connection properties and data source options.
+   * @return The {@link DataFrameReader} to read from RDBMS
+   * @throws HoodieException
+   */
+  private static DataFrameReader validatePropsAndGetDataFrameReader(final SparkSession session,
+                                                                    final TypedProperties properties)
+      throws HoodieException {
+    DataFrameReader dataFrameReader;
+    FSDataInputStream passwordFileStream = null;
+    try {
+      dataFrameReader = session.read().format("jdbc");
+      dataFrameReader = dataFrameReader.option(Config.URL_PROP, properties.getString(Config.URL));
+      dataFrameReader = dataFrameReader.option(Config.USER_PROP, properties.getString(Config.USER));
+      dataFrameReader = dataFrameReader.option(Config.DRIVER_PROP, properties.getString(Config.DRIVER_CLASS));
+      dataFrameReader = dataFrameReader
+          .option(Config.RDBMS_TABLE_PROP, properties.getString(Config.RDBMS_TABLE_NAME));
+
+      if (properties.containsKey(Config.PASSWORD)) {
+        LOG.info("Reading JDBC password from properties file....");
+        dataFrameReader = dataFrameReader.option(Config.PASSWORD_PROP, properties.getString(Config.PASSWORD));
+      } else if (properties.containsKey(Config.PASSWORD_FILE)
+          && !StringUtils.isNullOrEmpty(properties.getString(Config.PASSWORD_FILE))) {
+        LOG.info(String.format("Reading JDBC password from password file %s", properties.getString(Config.PASSWORD_FILE)));
+        FileSystem fileSystem = FileSystem.get(session.sparkContext().hadoopConfiguration());
+        passwordFileStream = fileSystem.open(new Path(properties.getString(Config.PASSWORD_FILE)));
+        byte[] bytes = new byte[passwordFileStream.available()];
+        passwordFileStream.read(bytes);
+        dataFrameReader = dataFrameReader.option(Config.PASSWORD_PROP, new String(bytes));
+      } else {
+        throw new IllegalArgumentException(String.format("JDBCSource needs either a %s or %s to connect to RDBMS "
+            + "datasource", Config.PASSWORD_FILE, Config.PASSWORD));
+      }
+
+      addExtraJdbcOptions(properties, dataFrameReader);
+
+      if (properties.getBoolean(Config.IS_INCREMENTAL)) {
+        DataSourceUtils.checkRequiredProperties(properties, Collections.singletonList(Config.INCREMENTAL_COLUMN));
+      }
+      return dataFrameReader;
+    } catch (Exception e) {
+      throw new HoodieException(e);
+    } finally {
+      IOUtils.closeStream(passwordFileStream);
+    }
+  }
+
+  /**
+   * Accepts spark JDBC options from the user in terms of EXTRA_OPTIONS adds them to {@link DataFrameReader} Example: In
+   * a normal spark code you would do something like: session.read.format('jdbc') .option(fetchSize,1000)
+   * .option(timestampFormat,"yyyy-mm-dd hh:mm:ss")
+   * <p>
+   * The way to pass these properties to HUDI is through the config file. Any property starting with
+   * hoodie.datasource.jdbc.extra.options. will be added.
+   * <p>
+   * Example: hoodie.datasource.jdbc.extra.options.fetchSize=100
+   * hoodie.datasource.jdbc.extra.options.upperBound=1
+   * hoodie.datasource.jdbc.extra.options.lowerBound=100
+   *
+   * @param properties      The JDBC connection properties and data source options.
+   * @param dataFrameReader The {@link DataFrameReader} to which data source options will be added.
+   */
+  private static void addExtraJdbcOptions(TypedProperties properties, DataFrameReader dataFrameReader) {
+    Set<Object> objects = properties.keySet();
+    for (Object property : objects) {
+      String prop = (String) property;
+      if (prop.startsWith(Config.EXTRA_OPTIONS)) {
+        String key = String.join("", prop.split(Config.EXTRA_OPTIONS));
+        String value = properties.getString(prop);
+        if (!StringUtils.isNullOrEmpty(value)) {
+          LOG.info(String.format("Adding %s -> %s to jdbc options", key, value));
+          dataFrameReader.option(key, value);
+        }
+      }
+    }
+  }
+
+  @Override
+  protected Pair<Option<Dataset<Row>>, String> fetchNextBatch(Option<String> lastCkptStr, long sourceLimit) {
+    try {
+      DataSourceUtils.checkRequiredProperties(props, Arrays.asList(Config.URL, Config.DRIVER_CLASS, Config.USER, Config.RDBMS_TABLE_NAME, Config.IS_INCREMENTAL));
+      return fetch(lastCkptStr, sourceLimit);
+    } catch (Exception e) {
+      LOG.error("Exception while running JDBCSource ", e);
+      return Pair.of(Option.empty(), null);
+    }
+  }
+
+  /**
+   * Decide to do a full RDBMS table scan or an incremental scan based on the lastCkptStr. If previous checkpoint
+   * value exists then we do an incremental scan with a PPD query or else we do a full scan. In certain cases where the
+   * incremental query fails, we fallback to a full scan.
+   *
+   * @param lastCkptStr Last checkpoint.
+   * @return The pair of {@link Dataset} and current checkpoint.
+   */
+  @NotNull
+  private Pair<Option<Dataset<Row>>, String> fetch(Option<String> lastCkptStr, long sourceLimit) {
+    Dataset<Row> dataset;
+    if (lastCkptStr.isPresent() && !StringUtils.isNullOrEmpty(lastCkptStr.get())) {
+      dataset = incrementalFetch(lastCkptStr, sourceLimit);
+    } else {
+      LOG.info("No checkpoint references found. Doing a full rdbms table fetch");
+      dataset = fullFetch();
+    }
+
+    if (props.containsKey(Config.STORAGE_LEVEL) && !StringUtils.isNullOrEmpty(props.getString(Config.STORAGE_LEVEL))) {
+      dataset.persist(StorageLevel.fromString(props.getString(Config.STORAGE_LEVEL)));
+    } else {
+      dataset.persist(StorageLevel.MEMORY_AND_DISK_SER());
+    }
+
+    boolean isIncremental = props.getBoolean(Config.IS_INCREMENTAL);
+    Pair<Option<Dataset<Row>>, String> pair = Pair.of(Option.of(dataset), checkpoint(dataset, isIncremental));
+    dataset.unpersist();
+
+    return pair;
+  }
+
+  /**
+   * Does an incremental scan with PPQ query prepared on the bases of previous checkpoint.
+   *
+   * @param lastCheckpoint Last checkpoint
+   * @return The {@link Dataset} after incremental fetch from RDBMS.
+   */
+  @NotNull
+  private Dataset<Row> incrementalFetch(Option<String> lastCheckpoint, long sourceLimit) {
+    try {
+      final String ppdQuery = "(%s) rdbms_table";
+      final SqlQueryBuilder queryBuilder = SqlQueryBuilder.select("*")
+          .from(props.getString(Config.RDBMS_TABLE_NAME))
+          .where(String.format(" %s > '%s'", props.getString(Config.INCREMENTAL_COLUMN), lastCheckpoint.get()));
+
+      if (sourceLimit > 0) {
+        URI jdbcURI = URI.create(props.getString(Config.URL).substring(URI_JDBC_PREFIX.length()));
+        if (DB_LIMIT_CLAUSE.contains(jdbcURI.getScheme())) {
+          queryBuilder.orderBy(props.getString(Config.INCREMENTAL_COLUMN)).limit(sourceLimit);
+        }
+      }
+
+      String query = String.format(ppdQuery, queryBuilder.toString());
+      LOG.error("PPD QUERY: " + query);

Review comment:
       +1 

##########
File path: hudi-utilities/src/main/java/org/apache/hudi/utilities/sources/JdbcSource.java
##########
@@ -0,0 +1,326 @@
+/*
+ * 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.hudi.utilities.sources;
+
+import org.apache.hudi.DataSourceUtils;
+import org.apache.hudi.common.config.TypedProperties;
+import org.apache.hudi.common.util.Option;
+import org.apache.hudi.common.util.StringUtils;
+import org.apache.hudi.common.util.collection.Pair;
+import org.apache.hudi.exception.HoodieException;
+import org.apache.hudi.utilities.SqlQueryBuilder;
+import org.apache.hudi.utilities.schema.SchemaProvider;
+
+import org.apache.hadoop.fs.FSDataInputStream;
+import org.apache.hadoop.fs.FileSystem;
+import org.apache.hadoop.fs.Path;
+import org.apache.hadoop.io.IOUtils;
+import org.apache.log4j.LogManager;
+import org.apache.log4j.Logger;
+import org.apache.spark.api.java.JavaSparkContext;
+import org.apache.spark.sql.Column;
+import org.apache.spark.sql.DataFrameReader;
+import org.apache.spark.sql.Dataset;
+import org.apache.spark.sql.Row;
+import org.apache.spark.sql.SparkSession;
+import org.apache.spark.sql.functions;
+import org.apache.spark.sql.types.DataTypes;
+import org.apache.spark.storage.StorageLevel;
+import org.jetbrains.annotations.NotNull;
+
+import java.net.URI;
+import java.util.Arrays;
+import java.util.Collections;
+import java.util.List;
+import java.util.Set;
+
+/**
+ * Reads data from RDBMS data sources.
+ */
+
+public class JdbcSource extends RowSource {
+
+  private static final Logger LOG = LogManager.getLogger(JdbcSource.class);
+  private static final List<String> DB_LIMIT_CLAUSE = Arrays.asList("mysql", "postgresql", "h2");
+  private static final String URI_JDBC_PREFIX = "jdbc:";
+
+  public JdbcSource(TypedProperties props, JavaSparkContext sparkContext, SparkSession sparkSession,
+                    SchemaProvider schemaProvider) {
+    super(props, sparkContext, sparkSession, schemaProvider);
+  }
+
+  /**
+   * Validates all user properties and prepares the {@link DataFrameReader} to read from RDBMS.
+   *
+   * @param session    The {@link SparkSession}.
+   * @param properties The JDBC connection properties and data source options.
+   * @return The {@link DataFrameReader} to read from RDBMS
+   * @throws HoodieException
+   */
+  private static DataFrameReader validatePropsAndGetDataFrameReader(final SparkSession session,
+                                                                    final TypedProperties properties)
+      throws HoodieException {
+    DataFrameReader dataFrameReader;
+    FSDataInputStream passwordFileStream = null;
+    try {
+      dataFrameReader = session.read().format("jdbc");
+      dataFrameReader = dataFrameReader.option(Config.URL_PROP, properties.getString(Config.URL));
+      dataFrameReader = dataFrameReader.option(Config.USER_PROP, properties.getString(Config.USER));
+      dataFrameReader = dataFrameReader.option(Config.DRIVER_PROP, properties.getString(Config.DRIVER_CLASS));
+      dataFrameReader = dataFrameReader
+          .option(Config.RDBMS_TABLE_PROP, properties.getString(Config.RDBMS_TABLE_NAME));
+
+      if (properties.containsKey(Config.PASSWORD)) {
+        LOG.info("Reading JDBC password from properties file....");
+        dataFrameReader = dataFrameReader.option(Config.PASSWORD_PROP, properties.getString(Config.PASSWORD));
+      } else if (properties.containsKey(Config.PASSWORD_FILE)
+          && !StringUtils.isNullOrEmpty(properties.getString(Config.PASSWORD_FILE))) {
+        LOG.info(String.format("Reading JDBC password from password file %s", properties.getString(Config.PASSWORD_FILE)));
+        FileSystem fileSystem = FileSystem.get(session.sparkContext().hadoopConfiguration());
+        passwordFileStream = fileSystem.open(new Path(properties.getString(Config.PASSWORD_FILE)));
+        byte[] bytes = new byte[passwordFileStream.available()];
+        passwordFileStream.read(bytes);
+        dataFrameReader = dataFrameReader.option(Config.PASSWORD_PROP, new String(bytes));
+      } else {
+        throw new IllegalArgumentException(String.format("JDBCSource needs either a %s or %s to connect to RDBMS "
+            + "datasource", Config.PASSWORD_FILE, Config.PASSWORD));
+      }
+
+      addExtraJdbcOptions(properties, dataFrameReader);
+
+      if (properties.getBoolean(Config.IS_INCREMENTAL)) {
+        DataSourceUtils.checkRequiredProperties(properties, Collections.singletonList(Config.INCREMENTAL_COLUMN));
+      }
+      return dataFrameReader;
+    } catch (Exception e) {
+      throw new HoodieException(e);
+    } finally {
+      IOUtils.closeStream(passwordFileStream);
+    }
+  }
+
+  /**
+   * Accepts spark JDBC options from the user in terms of EXTRA_OPTIONS adds them to {@link DataFrameReader} Example: In
+   * a normal spark code you would do something like: session.read.format('jdbc') .option(fetchSize,1000)
+   * .option(timestampFormat,"yyyy-mm-dd hh:mm:ss")
+   * <p>
+   * The way to pass these properties to HUDI is through the config file. Any property starting with
+   * hoodie.datasource.jdbc.extra.options. will be added.
+   * <p>
+   * Example: hoodie.datasource.jdbc.extra.options.fetchSize=100
+   * hoodie.datasource.jdbc.extra.options.upperBound=1
+   * hoodie.datasource.jdbc.extra.options.lowerBound=100
+   *
+   * @param properties      The JDBC connection properties and data source options.
+   * @param dataFrameReader The {@link DataFrameReader} to which data source options will be added.
+   */
+  private static void addExtraJdbcOptions(TypedProperties properties, DataFrameReader dataFrameReader) {
+    Set<Object> objects = properties.keySet();
+    for (Object property : objects) {
+      String prop = (String) property;

Review comment:
       can we use `property.toString()` instead? 

##########
File path: hudi-utilities/src/main/java/org/apache/hudi/utilities/sources/JdbcSource.java
##########
@@ -0,0 +1,326 @@
+/*
+ * 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.hudi.utilities.sources;
+
+import org.apache.hudi.DataSourceUtils;
+import org.apache.hudi.common.config.TypedProperties;
+import org.apache.hudi.common.util.Option;
+import org.apache.hudi.common.util.StringUtils;
+import org.apache.hudi.common.util.collection.Pair;
+import org.apache.hudi.exception.HoodieException;
+import org.apache.hudi.utilities.SqlQueryBuilder;
+import org.apache.hudi.utilities.schema.SchemaProvider;
+
+import org.apache.hadoop.fs.FSDataInputStream;
+import org.apache.hadoop.fs.FileSystem;
+import org.apache.hadoop.fs.Path;
+import org.apache.hadoop.io.IOUtils;
+import org.apache.log4j.LogManager;
+import org.apache.log4j.Logger;
+import org.apache.spark.api.java.JavaSparkContext;
+import org.apache.spark.sql.Column;
+import org.apache.spark.sql.DataFrameReader;
+import org.apache.spark.sql.Dataset;
+import org.apache.spark.sql.Row;
+import org.apache.spark.sql.SparkSession;
+import org.apache.spark.sql.functions;
+import org.apache.spark.sql.types.DataTypes;
+import org.apache.spark.storage.StorageLevel;
+import org.jetbrains.annotations.NotNull;
+
+import java.net.URI;
+import java.util.Arrays;
+import java.util.Collections;
+import java.util.List;
+import java.util.Set;
+
+/**
+ * Reads data from RDBMS data sources.
+ */
+
+public class JdbcSource extends RowSource {
+
+  private static final Logger LOG = LogManager.getLogger(JdbcSource.class);
+  private static final List<String> DB_LIMIT_CLAUSE = Arrays.asList("mysql", "postgresql", "h2");
+  private static final String URI_JDBC_PREFIX = "jdbc:";
+
+  public JdbcSource(TypedProperties props, JavaSparkContext sparkContext, SparkSession sparkSession,
+                    SchemaProvider schemaProvider) {
+    super(props, sparkContext, sparkSession, schemaProvider);
+  }
+
+  /**
+   * Validates all user properties and prepares the {@link DataFrameReader} to read from RDBMS.
+   *
+   * @param session    The {@link SparkSession}.
+   * @param properties The JDBC connection properties and data source options.
+   * @return The {@link DataFrameReader} to read from RDBMS
+   * @throws HoodieException
+   */
+  private static DataFrameReader validatePropsAndGetDataFrameReader(final SparkSession session,
+                                                                    final TypedProperties properties)
+      throws HoodieException {
+    DataFrameReader dataFrameReader;
+    FSDataInputStream passwordFileStream = null;
+    try {
+      dataFrameReader = session.read().format("jdbc");
+      dataFrameReader = dataFrameReader.option(Config.URL_PROP, properties.getString(Config.URL));
+      dataFrameReader = dataFrameReader.option(Config.USER_PROP, properties.getString(Config.USER));
+      dataFrameReader = dataFrameReader.option(Config.DRIVER_PROP, properties.getString(Config.DRIVER_CLASS));
+      dataFrameReader = dataFrameReader
+          .option(Config.RDBMS_TABLE_PROP, properties.getString(Config.RDBMS_TABLE_NAME));
+
+      if (properties.containsKey(Config.PASSWORD)) {
+        LOG.info("Reading JDBC password from properties file....");
+        dataFrameReader = dataFrameReader.option(Config.PASSWORD_PROP, properties.getString(Config.PASSWORD));
+      } else if (properties.containsKey(Config.PASSWORD_FILE)
+          && !StringUtils.isNullOrEmpty(properties.getString(Config.PASSWORD_FILE))) {
+        LOG.info(String.format("Reading JDBC password from password file %s", properties.getString(Config.PASSWORD_FILE)));
+        FileSystem fileSystem = FileSystem.get(session.sparkContext().hadoopConfiguration());
+        passwordFileStream = fileSystem.open(new Path(properties.getString(Config.PASSWORD_FILE)));
+        byte[] bytes = new byte[passwordFileStream.available()];
+        passwordFileStream.read(bytes);
+        dataFrameReader = dataFrameReader.option(Config.PASSWORD_PROP, new String(bytes));
+      } else {
+        throw new IllegalArgumentException(String.format("JDBCSource needs either a %s or %s to connect to RDBMS "
+            + "datasource", Config.PASSWORD_FILE, Config.PASSWORD));
+      }
+
+      addExtraJdbcOptions(properties, dataFrameReader);
+
+      if (properties.getBoolean(Config.IS_INCREMENTAL)) {
+        DataSourceUtils.checkRequiredProperties(properties, Collections.singletonList(Config.INCREMENTAL_COLUMN));
+      }
+      return dataFrameReader;
+    } catch (Exception e) {
+      throw new HoodieException(e);
+    } finally {
+      IOUtils.closeStream(passwordFileStream);
+    }
+  }
+
+  /**
+   * Accepts spark JDBC options from the user in terms of EXTRA_OPTIONS adds them to {@link DataFrameReader} Example: In
+   * a normal spark code you would do something like: session.read.format('jdbc') .option(fetchSize,1000)
+   * .option(timestampFormat,"yyyy-mm-dd hh:mm:ss")
+   * <p>
+   * The way to pass these properties to HUDI is through the config file. Any property starting with
+   * hoodie.datasource.jdbc.extra.options. will be added.
+   * <p>
+   * Example: hoodie.datasource.jdbc.extra.options.fetchSize=100
+   * hoodie.datasource.jdbc.extra.options.upperBound=1
+   * hoodie.datasource.jdbc.extra.options.lowerBound=100
+   *
+   * @param properties      The JDBC connection properties and data source options.
+   * @param dataFrameReader The {@link DataFrameReader} to which data source options will be added.
+   */
+  private static void addExtraJdbcOptions(TypedProperties properties, DataFrameReader dataFrameReader) {
+    Set<Object> objects = properties.keySet();
+    for (Object property : objects) {
+      String prop = (String) property;
+      if (prop.startsWith(Config.EXTRA_OPTIONS)) {
+        String key = String.join("", prop.split(Config.EXTRA_OPTIONS));
+        String value = properties.getString(prop);
+        if (!StringUtils.isNullOrEmpty(value)) {
+          LOG.info(String.format("Adding %s -> %s to jdbc options", key, value));
+          dataFrameReader.option(key, value);
+        }
+      }
+    }
+  }
+
+  @Override
+  protected Pair<Option<Dataset<Row>>, String> fetchNextBatch(Option<String> lastCkptStr, long sourceLimit) {
+    try {
+      DataSourceUtils.checkRequiredProperties(props, Arrays.asList(Config.URL, Config.DRIVER_CLASS, Config.USER, Config.RDBMS_TABLE_NAME, Config.IS_INCREMENTAL));
+      return fetch(lastCkptStr, sourceLimit);
+    } catch (Exception e) {
+      LOG.error("Exception while running JDBCSource ", e);
+      return Pair.of(Option.empty(), null);
+    }
+  }
+
+  /**
+   * Decide to do a full RDBMS table scan or an incremental scan based on the lastCkptStr. If previous checkpoint
+   * value exists then we do an incremental scan with a PPD query or else we do a full scan. In certain cases where the
+   * incremental query fails, we fallback to a full scan.
+   *
+   * @param lastCkptStr Last checkpoint.
+   * @return The pair of {@link Dataset} and current checkpoint.
+   */
+  @NotNull
+  private Pair<Option<Dataset<Row>>, String> fetch(Option<String> lastCkptStr, long sourceLimit) {
+    Dataset<Row> dataset;
+    if (lastCkptStr.isPresent() && !StringUtils.isNullOrEmpty(lastCkptStr.get())) {
+      dataset = incrementalFetch(lastCkptStr, sourceLimit);
+    } else {
+      LOG.info("No checkpoint references found. Doing a full rdbms table fetch");
+      dataset = fullFetch();
+    }
+
+    if (props.containsKey(Config.STORAGE_LEVEL) && !StringUtils.isNullOrEmpty(props.getString(Config.STORAGE_LEVEL))) {
+      dataset.persist(StorageLevel.fromString(props.getString(Config.STORAGE_LEVEL)));
+    } else {
+      dataset.persist(StorageLevel.MEMORY_AND_DISK_SER());
+    }
+
+    boolean isIncremental = props.getBoolean(Config.IS_INCREMENTAL);
+    Pair<Option<Dataset<Row>>, String> pair = Pair.of(Option.of(dataset), checkpoint(dataset, isIncremental));
+    dataset.unpersist();
+
+    return pair;
+  }
+
+  /**
+   * Does an incremental scan with PPQ query prepared on the bases of previous checkpoint.
+   *
+   * @param lastCheckpoint Last checkpoint
+   * @return The {@link Dataset} after incremental fetch from RDBMS.
+   */
+  @NotNull
+  private Dataset<Row> incrementalFetch(Option<String> lastCheckpoint, long sourceLimit) {
+    try {
+      final String ppdQuery = "(%s) rdbms_table";
+      final SqlQueryBuilder queryBuilder = SqlQueryBuilder.select("*")
+          .from(props.getString(Config.RDBMS_TABLE_NAME))
+          .where(String.format(" %s > '%s'", props.getString(Config.INCREMENTAL_COLUMN), lastCheckpoint.get()));
+
+      if (sourceLimit > 0) {
+        URI jdbcURI = URI.create(props.getString(Config.URL).substring(URI_JDBC_PREFIX.length()));
+        if (DB_LIMIT_CLAUSE.contains(jdbcURI.getScheme())) {
+          queryBuilder.orderBy(props.getString(Config.INCREMENTAL_COLUMN)).limit(sourceLimit);
+        }
+      }
+
+      String query = String.format(ppdQuery, queryBuilder.toString());
+      LOG.error("PPD QUERY: " + query);
+      LOG.info(String.format("Referenced last checkpoint and prepared new predicate pushdown query for jdbc pull %s", query));
+
+      return validatePropsAndGetDataFrameReader(sparkSession, props).option(Config.RDBMS_TABLE_PROP, query).load();
+    } catch (Exception e) {
+      LOG.error("Error while performing an incremental fetch. Not all database support the PPD query we generate to do an incremental scan", e);
+      LOG.warn("Falling back to full scan.");
+
+      return fullFetch();
+    }
+  }
+
+  /**
+   * Does a full scan on the RDBMS data source.
+   *
+   * @return The {@link Dataset} after running full scan.
+   */
+  private Dataset<Row> fullFetch() {
+    return validatePropsAndGetDataFrameReader(sparkSession, props).load();
+  }
+
+  private String checkpoint(Dataset<Row> rowDataset, boolean isIncremental) {
+    try {
+      if (isIncremental) {
+        Column incrementalColumn = rowDataset.col(props.getString(Config.INCREMENTAL_COLUMN));
+        final String max = rowDataset.agg(functions.max(incrementalColumn).cast(DataTypes.StringType)).first().getString(0);
+        LOG.info(String.format("Checkpointing column %s with value: %s ", incrementalColumn, max));
+        return max;
+      } else {
+        return null;
+      }
+    } catch (Exception e) {
+      return null;
+    }
+  }
+
+  /**
+   * Inner class with config keys.
+   */
+  protected static class Config {
+
+    /**
+     * {@value #URL} is the jdbc url for the Hoodie datasource.
+     */
+    private static final String URL = "hoodie.datasource.jdbc.url";

Review comment:
       can we name these `hoodie.deltastreamer.jdbc....` ? consistent with other source props

##########
File path: hudi-utilities/src/main/java/org/apache/hudi/utilities/sources/JdbcSource.java
##########
@@ -0,0 +1,326 @@
+/*
+ * 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.hudi.utilities.sources;
+
+import org.apache.hudi.DataSourceUtils;
+import org.apache.hudi.common.config.TypedProperties;
+import org.apache.hudi.common.util.Option;
+import org.apache.hudi.common.util.StringUtils;
+import org.apache.hudi.common.util.collection.Pair;
+import org.apache.hudi.exception.HoodieException;
+import org.apache.hudi.utilities.SqlQueryBuilder;
+import org.apache.hudi.utilities.schema.SchemaProvider;
+
+import org.apache.hadoop.fs.FSDataInputStream;
+import org.apache.hadoop.fs.FileSystem;
+import org.apache.hadoop.fs.Path;
+import org.apache.hadoop.io.IOUtils;
+import org.apache.log4j.LogManager;
+import org.apache.log4j.Logger;
+import org.apache.spark.api.java.JavaSparkContext;
+import org.apache.spark.sql.Column;
+import org.apache.spark.sql.DataFrameReader;
+import org.apache.spark.sql.Dataset;
+import org.apache.spark.sql.Row;
+import org.apache.spark.sql.SparkSession;
+import org.apache.spark.sql.functions;
+import org.apache.spark.sql.types.DataTypes;
+import org.apache.spark.storage.StorageLevel;
+import org.jetbrains.annotations.NotNull;
+
+import java.net.URI;
+import java.util.Arrays;
+import java.util.Collections;
+import java.util.List;
+import java.util.Set;
+
+/**
+ * Reads data from RDBMS data sources.
+ */
+
+public class JdbcSource extends RowSource {
+
+  private static final Logger LOG = LogManager.getLogger(JdbcSource.class);
+  private static final List<String> DB_LIMIT_CLAUSE = Arrays.asList("mysql", "postgresql", "h2");
+  private static final String URI_JDBC_PREFIX = "jdbc:";
+
+  public JdbcSource(TypedProperties props, JavaSparkContext sparkContext, SparkSession sparkSession,
+                    SchemaProvider schemaProvider) {
+    super(props, sparkContext, sparkSession, schemaProvider);
+  }
+
+  /**
+   * Validates all user properties and prepares the {@link DataFrameReader} to read from RDBMS.
+   *
+   * @param session    The {@link SparkSession}.
+   * @param properties The JDBC connection properties and data source options.
+   * @return The {@link DataFrameReader} to read from RDBMS
+   * @throws HoodieException
+   */
+  private static DataFrameReader validatePropsAndGetDataFrameReader(final SparkSession session,
+                                                                    final TypedProperties properties)
+      throws HoodieException {
+    DataFrameReader dataFrameReader;
+    FSDataInputStream passwordFileStream = null;
+    try {
+      dataFrameReader = session.read().format("jdbc");
+      dataFrameReader = dataFrameReader.option(Config.URL_PROP, properties.getString(Config.URL));
+      dataFrameReader = dataFrameReader.option(Config.USER_PROP, properties.getString(Config.USER));
+      dataFrameReader = dataFrameReader.option(Config.DRIVER_PROP, properties.getString(Config.DRIVER_CLASS));
+      dataFrameReader = dataFrameReader
+          .option(Config.RDBMS_TABLE_PROP, properties.getString(Config.RDBMS_TABLE_NAME));
+
+      if (properties.containsKey(Config.PASSWORD)) {
+        LOG.info("Reading JDBC password from properties file....");
+        dataFrameReader = dataFrameReader.option(Config.PASSWORD_PROP, properties.getString(Config.PASSWORD));
+      } else if (properties.containsKey(Config.PASSWORD_FILE)
+          && !StringUtils.isNullOrEmpty(properties.getString(Config.PASSWORD_FILE))) {
+        LOG.info(String.format("Reading JDBC password from password file %s", properties.getString(Config.PASSWORD_FILE)));
+        FileSystem fileSystem = FileSystem.get(session.sparkContext().hadoopConfiguration());
+        passwordFileStream = fileSystem.open(new Path(properties.getString(Config.PASSWORD_FILE)));
+        byte[] bytes = new byte[passwordFileStream.available()];
+        passwordFileStream.read(bytes);
+        dataFrameReader = dataFrameReader.option(Config.PASSWORD_PROP, new String(bytes));
+      } else {
+        throw new IllegalArgumentException(String.format("JDBCSource needs either a %s or %s to connect to RDBMS "
+            + "datasource", Config.PASSWORD_FILE, Config.PASSWORD));
+      }
+
+      addExtraJdbcOptions(properties, dataFrameReader);
+
+      if (properties.getBoolean(Config.IS_INCREMENTAL)) {
+        DataSourceUtils.checkRequiredProperties(properties, Collections.singletonList(Config.INCREMENTAL_COLUMN));
+      }
+      return dataFrameReader;
+    } catch (Exception e) {
+      throw new HoodieException(e);
+    } finally {
+      IOUtils.closeStream(passwordFileStream);
+    }
+  }
+
+  /**
+   * Accepts spark JDBC options from the user in terms of EXTRA_OPTIONS adds them to {@link DataFrameReader} Example: In
+   * a normal spark code you would do something like: session.read.format('jdbc') .option(fetchSize,1000)
+   * .option(timestampFormat,"yyyy-mm-dd hh:mm:ss")
+   * <p>
+   * The way to pass these properties to HUDI is through the config file. Any property starting with
+   * hoodie.datasource.jdbc.extra.options. will be added.
+   * <p>
+   * Example: hoodie.datasource.jdbc.extra.options.fetchSize=100
+   * hoodie.datasource.jdbc.extra.options.upperBound=1
+   * hoodie.datasource.jdbc.extra.options.lowerBound=100
+   *
+   * @param properties      The JDBC connection properties and data source options.
+   * @param dataFrameReader The {@link DataFrameReader} to which data source options will be added.
+   */
+  private static void addExtraJdbcOptions(TypedProperties properties, DataFrameReader dataFrameReader) {
+    Set<Object> objects = properties.keySet();
+    for (Object property : objects) {
+      String prop = (String) property;
+      if (prop.startsWith(Config.EXTRA_OPTIONS)) {
+        String key = String.join("", prop.split(Config.EXTRA_OPTIONS));
+        String value = properties.getString(prop);
+        if (!StringUtils.isNullOrEmpty(value)) {
+          LOG.info(String.format("Adding %s -> %s to jdbc options", key, value));
+          dataFrameReader.option(key, value);
+        }
+      }
+    }
+  }
+
+  @Override
+  protected Pair<Option<Dataset<Row>>, String> fetchNextBatch(Option<String> lastCkptStr, long sourceLimit) {
+    try {
+      DataSourceUtils.checkRequiredProperties(props, Arrays.asList(Config.URL, Config.DRIVER_CLASS, Config.USER, Config.RDBMS_TABLE_NAME, Config.IS_INCREMENTAL));
+      return fetch(lastCkptStr, sourceLimit);
+    } catch (Exception e) {
+      LOG.error("Exception while running JDBCSource ", e);
+      return Pair.of(Option.empty(), null);
+    }
+  }
+
+  /**
+   * Decide to do a full RDBMS table scan or an incremental scan based on the lastCkptStr. If previous checkpoint
+   * value exists then we do an incremental scan with a PPD query or else we do a full scan. In certain cases where the
+   * incremental query fails, we fallback to a full scan.
+   *
+   * @param lastCkptStr Last checkpoint.
+   * @return The pair of {@link Dataset} and current checkpoint.
+   */
+  @NotNull
+  private Pair<Option<Dataset<Row>>, String> fetch(Option<String> lastCkptStr, long sourceLimit) {
+    Dataset<Row> dataset;
+    if (lastCkptStr.isPresent() && !StringUtils.isNullOrEmpty(lastCkptStr.get())) {
+      dataset = incrementalFetch(lastCkptStr, sourceLimit);
+    } else {
+      LOG.info("No checkpoint references found. Doing a full rdbms table fetch");
+      dataset = fullFetch();
+    }
+
+    if (props.containsKey(Config.STORAGE_LEVEL) && !StringUtils.isNullOrEmpty(props.getString(Config.STORAGE_LEVEL))) {
+      dataset.persist(StorageLevel.fromString(props.getString(Config.STORAGE_LEVEL)));
+    } else {
+      dataset.persist(StorageLevel.MEMORY_AND_DISK_SER());
+    }
+
+    boolean isIncremental = props.getBoolean(Config.IS_INCREMENTAL);
+    Pair<Option<Dataset<Row>>, String> pair = Pair.of(Option.of(dataset), checkpoint(dataset, isIncremental));
+    dataset.unpersist();
+
+    return pair;
+  }
+
+  /**
+   * Does an incremental scan with PPQ query prepared on the bases of previous checkpoint.
+   *
+   * @param lastCheckpoint Last checkpoint
+   * @return The {@link Dataset} after incremental fetch from RDBMS.
+   */
+  @NotNull
+  private Dataset<Row> incrementalFetch(Option<String> lastCheckpoint, long sourceLimit) {
+    try {
+      final String ppdQuery = "(%s) rdbms_table";
+      final SqlQueryBuilder queryBuilder = SqlQueryBuilder.select("*")
+          .from(props.getString(Config.RDBMS_TABLE_NAME))
+          .where(String.format(" %s > '%s'", props.getString(Config.INCREMENTAL_COLUMN), lastCheckpoint.get()));
+
+      if (sourceLimit > 0) {
+        URI jdbcURI = URI.create(props.getString(Config.URL).substring(URI_JDBC_PREFIX.length()));
+        if (DB_LIMIT_CLAUSE.contains(jdbcURI.getScheme())) {
+          queryBuilder.orderBy(props.getString(Config.INCREMENTAL_COLUMN)).limit(sourceLimit);
+        }
+      }
+
+      String query = String.format(ppdQuery, queryBuilder.toString());
+      LOG.error("PPD QUERY: " + query);
+      LOG.info(String.format("Referenced last checkpoint and prepared new predicate pushdown query for jdbc pull %s", query));
+
+      return validatePropsAndGetDataFrameReader(sparkSession, props).option(Config.RDBMS_TABLE_PROP, query).load();
+    } catch (Exception e) {
+      LOG.error("Error while performing an incremental fetch. Not all database support the PPD query we generate to do an incremental scan", e);
+      LOG.warn("Falling back to full scan.");
+
+      return fullFetch();
+    }
+  }
+
+  /**
+   * Does a full scan on the RDBMS data source.
+   *
+   * @return The {@link Dataset} after running full scan.
+   */
+  private Dataset<Row> fullFetch() {
+    return validatePropsAndGetDataFrameReader(sparkSession, props).load();
+  }
+
+  private String checkpoint(Dataset<Row> rowDataset, boolean isIncremental) {
+    try {
+      if (isIncremental) {
+        Column incrementalColumn = rowDataset.col(props.getString(Config.INCREMENTAL_COLUMN));
+        final String max = rowDataset.agg(functions.max(incrementalColumn).cast(DataTypes.StringType)).first().getString(0);
+        LOG.info(String.format("Checkpointing column %s with value: %s ", incrementalColumn, max));
+        return max;
+      } else {
+        return null;
+      }
+    } catch (Exception e) {
+      return null;

Review comment:
       +1 lets not please return null :) 

##########
File path: hudi-utilities/src/main/java/org/apache/hudi/utilities/sources/JdbcSource.java
##########
@@ -0,0 +1,326 @@
+/*
+ * 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.hudi.utilities.sources;
+
+import org.apache.hudi.DataSourceUtils;
+import org.apache.hudi.common.config.TypedProperties;
+import org.apache.hudi.common.util.Option;
+import org.apache.hudi.common.util.StringUtils;
+import org.apache.hudi.common.util.collection.Pair;
+import org.apache.hudi.exception.HoodieException;
+import org.apache.hudi.utilities.SqlQueryBuilder;
+import org.apache.hudi.utilities.schema.SchemaProvider;
+
+import org.apache.hadoop.fs.FSDataInputStream;
+import org.apache.hadoop.fs.FileSystem;
+import org.apache.hadoop.fs.Path;
+import org.apache.hadoop.io.IOUtils;
+import org.apache.log4j.LogManager;
+import org.apache.log4j.Logger;
+import org.apache.spark.api.java.JavaSparkContext;
+import org.apache.spark.sql.Column;
+import org.apache.spark.sql.DataFrameReader;
+import org.apache.spark.sql.Dataset;
+import org.apache.spark.sql.Row;
+import org.apache.spark.sql.SparkSession;
+import org.apache.spark.sql.functions;
+import org.apache.spark.sql.types.DataTypes;
+import org.apache.spark.storage.StorageLevel;
+import org.jetbrains.annotations.NotNull;
+
+import java.net.URI;
+import java.util.Arrays;
+import java.util.Collections;
+import java.util.List;
+import java.util.Set;
+
+/**
+ * Reads data from RDBMS data sources.
+ */
+
+public class JdbcSource extends RowSource {
+
+  private static final Logger LOG = LogManager.getLogger(JdbcSource.class);
+  private static final List<String> DB_LIMIT_CLAUSE = Arrays.asList("mysql", "postgresql", "h2");
+  private static final String URI_JDBC_PREFIX = "jdbc:";
+
+  public JdbcSource(TypedProperties props, JavaSparkContext sparkContext, SparkSession sparkSession,
+                    SchemaProvider schemaProvider) {
+    super(props, sparkContext, sparkSession, schemaProvider);
+  }
+
+  /**
+   * Validates all user properties and prepares the {@link DataFrameReader} to read from RDBMS.
+   *
+   * @param session    The {@link SparkSession}.
+   * @param properties The JDBC connection properties and data source options.
+   * @return The {@link DataFrameReader} to read from RDBMS
+   * @throws HoodieException
+   */
+  private static DataFrameReader validatePropsAndGetDataFrameReader(final SparkSession session,
+                                                                    final TypedProperties properties)
+      throws HoodieException {
+    DataFrameReader dataFrameReader;
+    FSDataInputStream passwordFileStream = null;
+    try {
+      dataFrameReader = session.read().format("jdbc");
+      dataFrameReader = dataFrameReader.option(Config.URL_PROP, properties.getString(Config.URL));
+      dataFrameReader = dataFrameReader.option(Config.USER_PROP, properties.getString(Config.USER));
+      dataFrameReader = dataFrameReader.option(Config.DRIVER_PROP, properties.getString(Config.DRIVER_CLASS));
+      dataFrameReader = dataFrameReader
+          .option(Config.RDBMS_TABLE_PROP, properties.getString(Config.RDBMS_TABLE_NAME));
+
+      if (properties.containsKey(Config.PASSWORD)) {
+        LOG.info("Reading JDBC password from properties file....");
+        dataFrameReader = dataFrameReader.option(Config.PASSWORD_PROP, properties.getString(Config.PASSWORD));
+      } else if (properties.containsKey(Config.PASSWORD_FILE)
+          && !StringUtils.isNullOrEmpty(properties.getString(Config.PASSWORD_FILE))) {
+        LOG.info(String.format("Reading JDBC password from password file %s", properties.getString(Config.PASSWORD_FILE)));
+        FileSystem fileSystem = FileSystem.get(session.sparkContext().hadoopConfiguration());
+        passwordFileStream = fileSystem.open(new Path(properties.getString(Config.PASSWORD_FILE)));
+        byte[] bytes = new byte[passwordFileStream.available()];
+        passwordFileStream.read(bytes);
+        dataFrameReader = dataFrameReader.option(Config.PASSWORD_PROP, new String(bytes));
+      } else {
+        throw new IllegalArgumentException(String.format("JDBCSource needs either a %s or %s to connect to RDBMS "
+            + "datasource", Config.PASSWORD_FILE, Config.PASSWORD));
+      }
+
+      addExtraJdbcOptions(properties, dataFrameReader);
+
+      if (properties.getBoolean(Config.IS_INCREMENTAL)) {
+        DataSourceUtils.checkRequiredProperties(properties, Collections.singletonList(Config.INCREMENTAL_COLUMN));

Review comment:
       +1 . we can add some validation of column types used as checkpoint. 

##########
File path: hudi-utilities/src/main/java/org/apache/hudi/utilities/sources/JdbcSource.java
##########
@@ -0,0 +1,326 @@
+/*
+ * 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.hudi.utilities.sources;
+
+import org.apache.hudi.DataSourceUtils;
+import org.apache.hudi.common.config.TypedProperties;
+import org.apache.hudi.common.util.Option;
+import org.apache.hudi.common.util.StringUtils;
+import org.apache.hudi.common.util.collection.Pair;
+import org.apache.hudi.exception.HoodieException;
+import org.apache.hudi.utilities.SqlQueryBuilder;
+import org.apache.hudi.utilities.schema.SchemaProvider;
+
+import org.apache.hadoop.fs.FSDataInputStream;
+import org.apache.hadoop.fs.FileSystem;
+import org.apache.hadoop.fs.Path;
+import org.apache.hadoop.io.IOUtils;
+import org.apache.log4j.LogManager;
+import org.apache.log4j.Logger;
+import org.apache.spark.api.java.JavaSparkContext;
+import org.apache.spark.sql.Column;
+import org.apache.spark.sql.DataFrameReader;
+import org.apache.spark.sql.Dataset;
+import org.apache.spark.sql.Row;
+import org.apache.spark.sql.SparkSession;
+import org.apache.spark.sql.functions;
+import org.apache.spark.sql.types.DataTypes;
+import org.apache.spark.storage.StorageLevel;
+import org.jetbrains.annotations.NotNull;
+
+import java.net.URI;
+import java.util.Arrays;
+import java.util.Collections;
+import java.util.List;
+import java.util.Set;
+
+/**
+ * Reads data from RDBMS data sources.
+ */
+
+public class JdbcSource extends RowSource {
+
+  private static final Logger LOG = LogManager.getLogger(JdbcSource.class);
+  private static final List<String> DB_LIMIT_CLAUSE = Arrays.asList("mysql", "postgresql", "h2");
+  private static final String URI_JDBC_PREFIX = "jdbc:";
+
+  public JdbcSource(TypedProperties props, JavaSparkContext sparkContext, SparkSession sparkSession,
+                    SchemaProvider schemaProvider) {
+    super(props, sparkContext, sparkSession, schemaProvider);
+  }
+
+  /**
+   * Validates all user properties and prepares the {@link DataFrameReader} to read from RDBMS.
+   *
+   * @param session    The {@link SparkSession}.
+   * @param properties The JDBC connection properties and data source options.
+   * @return The {@link DataFrameReader} to read from RDBMS
+   * @throws HoodieException
+   */
+  private static DataFrameReader validatePropsAndGetDataFrameReader(final SparkSession session,
+                                                                    final TypedProperties properties)
+      throws HoodieException {
+    DataFrameReader dataFrameReader;
+    FSDataInputStream passwordFileStream = null;
+    try {
+      dataFrameReader = session.read().format("jdbc");
+      dataFrameReader = dataFrameReader.option(Config.URL_PROP, properties.getString(Config.URL));
+      dataFrameReader = dataFrameReader.option(Config.USER_PROP, properties.getString(Config.USER));
+      dataFrameReader = dataFrameReader.option(Config.DRIVER_PROP, properties.getString(Config.DRIVER_CLASS));
+      dataFrameReader = dataFrameReader
+          .option(Config.RDBMS_TABLE_PROP, properties.getString(Config.RDBMS_TABLE_NAME));
+
+      if (properties.containsKey(Config.PASSWORD)) {
+        LOG.info("Reading JDBC password from properties file....");
+        dataFrameReader = dataFrameReader.option(Config.PASSWORD_PROP, properties.getString(Config.PASSWORD));
+      } else if (properties.containsKey(Config.PASSWORD_FILE)
+          && !StringUtils.isNullOrEmpty(properties.getString(Config.PASSWORD_FILE))) {
+        LOG.info(String.format("Reading JDBC password from password file %s", properties.getString(Config.PASSWORD_FILE)));
+        FileSystem fileSystem = FileSystem.get(session.sparkContext().hadoopConfiguration());
+        passwordFileStream = fileSystem.open(new Path(properties.getString(Config.PASSWORD_FILE)));
+        byte[] bytes = new byte[passwordFileStream.available()];
+        passwordFileStream.read(bytes);
+        dataFrameReader = dataFrameReader.option(Config.PASSWORD_PROP, new String(bytes));
+      } else {
+        throw new IllegalArgumentException(String.format("JDBCSource needs either a %s or %s to connect to RDBMS "
+            + "datasource", Config.PASSWORD_FILE, Config.PASSWORD));
+      }
+
+      addExtraJdbcOptions(properties, dataFrameReader);
+
+      if (properties.getBoolean(Config.IS_INCREMENTAL)) {
+        DataSourceUtils.checkRequiredProperties(properties, Collections.singletonList(Config.INCREMENTAL_COLUMN));
+      }
+      return dataFrameReader;
+    } catch (Exception e) {
+      throw new HoodieException(e);
+    } finally {
+      IOUtils.closeStream(passwordFileStream);
+    }
+  }
+
+  /**
+   * Accepts spark JDBC options from the user in terms of EXTRA_OPTIONS adds them to {@link DataFrameReader} Example: In
+   * a normal spark code you would do something like: session.read.format('jdbc') .option(fetchSize,1000)
+   * .option(timestampFormat,"yyyy-mm-dd hh:mm:ss")
+   * <p>
+   * The way to pass these properties to HUDI is through the config file. Any property starting with
+   * hoodie.datasource.jdbc.extra.options. will be added.
+   * <p>
+   * Example: hoodie.datasource.jdbc.extra.options.fetchSize=100
+   * hoodie.datasource.jdbc.extra.options.upperBound=1
+   * hoodie.datasource.jdbc.extra.options.lowerBound=100
+   *
+   * @param properties      The JDBC connection properties and data source options.
+   * @param dataFrameReader The {@link DataFrameReader} to which data source options will be added.
+   */
+  private static void addExtraJdbcOptions(TypedProperties properties, DataFrameReader dataFrameReader) {
+    Set<Object> objects = properties.keySet();
+    for (Object property : objects) {
+      String prop = (String) property;
+      if (prop.startsWith(Config.EXTRA_OPTIONS)) {
+        String key = String.join("", prop.split(Config.EXTRA_OPTIONS));
+        String value = properties.getString(prop);
+        if (!StringUtils.isNullOrEmpty(value)) {
+          LOG.info(String.format("Adding %s -> %s to jdbc options", key, value));
+          dataFrameReader.option(key, value);
+        }
+      }
+    }
+  }
+
+  @Override
+  protected Pair<Option<Dataset<Row>>, String> fetchNextBatch(Option<String> lastCkptStr, long sourceLimit) {
+    try {
+      DataSourceUtils.checkRequiredProperties(props, Arrays.asList(Config.URL, Config.DRIVER_CLASS, Config.USER, Config.RDBMS_TABLE_NAME, Config.IS_INCREMENTAL));
+      return fetch(lastCkptStr, sourceLimit);
+    } catch (Exception e) {
+      LOG.error("Exception while running JDBCSource ", e);
+      return Pair.of(Option.empty(), null);
+    }
+  }
+
+  /**
+   * Decide to do a full RDBMS table scan or an incremental scan based on the lastCkptStr. If previous checkpoint
+   * value exists then we do an incremental scan with a PPD query or else we do a full scan. In certain cases where the
+   * incremental query fails, we fallback to a full scan.
+   *
+   * @param lastCkptStr Last checkpoint.
+   * @return The pair of {@link Dataset} and current checkpoint.
+   */
+  @NotNull
+  private Pair<Option<Dataset<Row>>, String> fetch(Option<String> lastCkptStr, long sourceLimit) {
+    Dataset<Row> dataset;
+    if (lastCkptStr.isPresent() && !StringUtils.isNullOrEmpty(lastCkptStr.get())) {

Review comment:
       Not sure if this is needed right @nsivabalan ?  This is no different from Kafka source not having any offsets checkpointed already. We can simply pull the entire table.

##########
File path: hudi-utilities/src/main/java/org/apache/hudi/utilities/sources/JdbcSource.java
##########
@@ -0,0 +1,326 @@
+/*
+ * 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.hudi.utilities.sources;
+
+import org.apache.hudi.DataSourceUtils;
+import org.apache.hudi.common.config.TypedProperties;
+import org.apache.hudi.common.util.Option;
+import org.apache.hudi.common.util.StringUtils;
+import org.apache.hudi.common.util.collection.Pair;
+import org.apache.hudi.exception.HoodieException;
+import org.apache.hudi.utilities.SqlQueryBuilder;
+import org.apache.hudi.utilities.schema.SchemaProvider;
+
+import org.apache.hadoop.fs.FSDataInputStream;
+import org.apache.hadoop.fs.FileSystem;
+import org.apache.hadoop.fs.Path;
+import org.apache.hadoop.io.IOUtils;
+import org.apache.log4j.LogManager;
+import org.apache.log4j.Logger;
+import org.apache.spark.api.java.JavaSparkContext;
+import org.apache.spark.sql.Column;
+import org.apache.spark.sql.DataFrameReader;
+import org.apache.spark.sql.Dataset;
+import org.apache.spark.sql.Row;
+import org.apache.spark.sql.SparkSession;
+import org.apache.spark.sql.functions;
+import org.apache.spark.sql.types.DataTypes;
+import org.apache.spark.storage.StorageLevel;
+import org.jetbrains.annotations.NotNull;
+
+import java.net.URI;
+import java.util.Arrays;
+import java.util.Collections;
+import java.util.List;
+import java.util.Set;
+
+/**
+ * Reads data from RDBMS data sources.
+ */
+
+public class JdbcSource extends RowSource {
+
+  private static final Logger LOG = LogManager.getLogger(JdbcSource.class);
+  private static final List<String> DB_LIMIT_CLAUSE = Arrays.asList("mysql", "postgresql", "h2");
+  private static final String URI_JDBC_PREFIX = "jdbc:";
+
+  public JdbcSource(TypedProperties props, JavaSparkContext sparkContext, SparkSession sparkSession,
+                    SchemaProvider schemaProvider) {
+    super(props, sparkContext, sparkSession, schemaProvider);
+  }
+
+  /**
+   * Validates all user properties and prepares the {@link DataFrameReader} to read from RDBMS.
+   *
+   * @param session    The {@link SparkSession}.
+   * @param properties The JDBC connection properties and data source options.
+   * @return The {@link DataFrameReader} to read from RDBMS
+   * @throws HoodieException
+   */
+  private static DataFrameReader validatePropsAndGetDataFrameReader(final SparkSession session,
+                                                                    final TypedProperties properties)
+      throws HoodieException {
+    DataFrameReader dataFrameReader;
+    FSDataInputStream passwordFileStream = null;
+    try {
+      dataFrameReader = session.read().format("jdbc");
+      dataFrameReader = dataFrameReader.option(Config.URL_PROP, properties.getString(Config.URL));
+      dataFrameReader = dataFrameReader.option(Config.USER_PROP, properties.getString(Config.USER));
+      dataFrameReader = dataFrameReader.option(Config.DRIVER_PROP, properties.getString(Config.DRIVER_CLASS));
+      dataFrameReader = dataFrameReader
+          .option(Config.RDBMS_TABLE_PROP, properties.getString(Config.RDBMS_TABLE_NAME));
+
+      if (properties.containsKey(Config.PASSWORD)) {
+        LOG.info("Reading JDBC password from properties file....");
+        dataFrameReader = dataFrameReader.option(Config.PASSWORD_PROP, properties.getString(Config.PASSWORD));
+      } else if (properties.containsKey(Config.PASSWORD_FILE)
+          && !StringUtils.isNullOrEmpty(properties.getString(Config.PASSWORD_FILE))) {
+        LOG.info(String.format("Reading JDBC password from password file %s", properties.getString(Config.PASSWORD_FILE)));
+        FileSystem fileSystem = FileSystem.get(session.sparkContext().hadoopConfiguration());
+        passwordFileStream = fileSystem.open(new Path(properties.getString(Config.PASSWORD_FILE)));
+        byte[] bytes = new byte[passwordFileStream.available()];
+        passwordFileStream.read(bytes);
+        dataFrameReader = dataFrameReader.option(Config.PASSWORD_PROP, new String(bytes));
+      } else {
+        throw new IllegalArgumentException(String.format("JDBCSource needs either a %s or %s to connect to RDBMS "
+            + "datasource", Config.PASSWORD_FILE, Config.PASSWORD));
+      }
+
+      addExtraJdbcOptions(properties, dataFrameReader);
+
+      if (properties.getBoolean(Config.IS_INCREMENTAL)) {
+        DataSourceUtils.checkRequiredProperties(properties, Collections.singletonList(Config.INCREMENTAL_COLUMN));
+      }
+      return dataFrameReader;
+    } catch (Exception e) {
+      throw new HoodieException(e);
+    } finally {
+      IOUtils.closeStream(passwordFileStream);
+    }
+  }
+
+  /**
+   * Accepts spark JDBC options from the user in terms of EXTRA_OPTIONS adds them to {@link DataFrameReader} Example: In
+   * a normal spark code you would do something like: session.read.format('jdbc') .option(fetchSize,1000)
+   * .option(timestampFormat,"yyyy-mm-dd hh:mm:ss")
+   * <p>
+   * The way to pass these properties to HUDI is through the config file. Any property starting with
+   * hoodie.datasource.jdbc.extra.options. will be added.
+   * <p>
+   * Example: hoodie.datasource.jdbc.extra.options.fetchSize=100
+   * hoodie.datasource.jdbc.extra.options.upperBound=1
+   * hoodie.datasource.jdbc.extra.options.lowerBound=100
+   *
+   * @param properties      The JDBC connection properties and data source options.
+   * @param dataFrameReader The {@link DataFrameReader} to which data source options will be added.
+   */
+  private static void addExtraJdbcOptions(TypedProperties properties, DataFrameReader dataFrameReader) {
+    Set<Object> objects = properties.keySet();
+    for (Object property : objects) {
+      String prop = (String) property;
+      if (prop.startsWith(Config.EXTRA_OPTIONS)) {
+        String key = String.join("", prop.split(Config.EXTRA_OPTIONS));
+        String value = properties.getString(prop);
+        if (!StringUtils.isNullOrEmpty(value)) {
+          LOG.info(String.format("Adding %s -> %s to jdbc options", key, value));
+          dataFrameReader.option(key, value);
+        }
+      }
+    }
+  }
+
+  @Override
+  protected Pair<Option<Dataset<Row>>, String> fetchNextBatch(Option<String> lastCkptStr, long sourceLimit) {
+    try {
+      DataSourceUtils.checkRequiredProperties(props, Arrays.asList(Config.URL, Config.DRIVER_CLASS, Config.USER, Config.RDBMS_TABLE_NAME, Config.IS_INCREMENTAL));
+      return fetch(lastCkptStr, sourceLimit);
+    } catch (Exception e) {
+      LOG.error("Exception while running JDBCSource ", e);
+      return Pair.of(Option.empty(), null);
+    }
+  }
+
+  /**
+   * Decide to do a full RDBMS table scan or an incremental scan based on the lastCkptStr. If previous checkpoint
+   * value exists then we do an incremental scan with a PPD query or else we do a full scan. In certain cases where the
+   * incremental query fails, we fallback to a full scan.
+   *
+   * @param lastCkptStr Last checkpoint.
+   * @return The pair of {@link Dataset} and current checkpoint.
+   */
+  @NotNull
+  private Pair<Option<Dataset<Row>>, String> fetch(Option<String> lastCkptStr, long sourceLimit) {
+    Dataset<Row> dataset;
+    if (lastCkptStr.isPresent() && !StringUtils.isNullOrEmpty(lastCkptStr.get())) {
+      dataset = incrementalFetch(lastCkptStr, sourceLimit);
+    } else {
+      LOG.info("No checkpoint references found. Doing a full rdbms table fetch");
+      dataset = fullFetch();
+    }
+
+    if (props.containsKey(Config.STORAGE_LEVEL) && !StringUtils.isNullOrEmpty(props.getString(Config.STORAGE_LEVEL))) {
+      dataset.persist(StorageLevel.fromString(props.getString(Config.STORAGE_LEVEL)));
+    } else {
+      dataset.persist(StorageLevel.MEMORY_AND_DISK_SER());
+    }
+
+    boolean isIncremental = props.getBoolean(Config.IS_INCREMENTAL);
+    Pair<Option<Dataset<Row>>, String> pair = Pair.of(Option.of(dataset), checkpoint(dataset, isIncremental));
+    dataset.unpersist();
+
+    return pair;
+  }
+
+  /**
+   * Does an incremental scan with PPQ query prepared on the bases of previous checkpoint.
+   *
+   * @param lastCheckpoint Last checkpoint
+   * @return The {@link Dataset} after incremental fetch from RDBMS.
+   */
+  @NotNull
+  private Dataset<Row> incrementalFetch(Option<String> lastCheckpoint, long sourceLimit) {
+    try {
+      final String ppdQuery = "(%s) rdbms_table";
+      final SqlQueryBuilder queryBuilder = SqlQueryBuilder.select("*")
+          .from(props.getString(Config.RDBMS_TABLE_NAME))
+          .where(String.format(" %s > '%s'", props.getString(Config.INCREMENTAL_COLUMN), lastCheckpoint.get()));
+
+      if (sourceLimit > 0) {
+        URI jdbcURI = URI.create(props.getString(Config.URL).substring(URI_JDBC_PREFIX.length()));
+        if (DB_LIMIT_CLAUSE.contains(jdbcURI.getScheme())) {
+          queryBuilder.orderBy(props.getString(Config.INCREMENTAL_COLUMN)).limit(sourceLimit);
+        }
+      }
+
+      String query = String.format(ppdQuery, queryBuilder.toString());
+      LOG.error("PPD QUERY: " + query);
+      LOG.info(String.format("Referenced last checkpoint and prepared new predicate pushdown query for jdbc pull %s", query));
+
+      return validatePropsAndGetDataFrameReader(sparkSession, props).option(Config.RDBMS_TABLE_PROP, query).load();
+    } catch (Exception e) {
+      LOG.error("Error while performing an incremental fetch. Not all database support the PPD query we generate to do an incremental scan", e);
+      LOG.warn("Falling back to full scan.");

Review comment:
       +1 for controlling this via a config.




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