spark 并行加载 greenplum 数据，为正确运行，需引入 spark 相关包和 greenplum 驱动。
<dependencies>
<!-- https://mvnrepository.com/artifact/org.apache.spark/spark-core -->
<dependency>
<groupId>org.apache.spark</groupId>
<artifactId>spark-core_2.11</artifactId>
<version>2.3.1</version>
</dependency>
<!-- https://mvnrepository.com/artifact/org.apache.spark/spark-sql -->
<dependency>
<groupId>org.apache.spark</groupId>
<artifactId>spark-sql_2.11</artifactId>
<version>2.3.1</version>
</dependency>
<!-- https://mvnrepository.com/artifact/com.pivotal/greenplum-jdbc -->
<dependency>
<groupId>com.pivotal</groupId>
<artifactId>greenplum-jdbc</artifactId>
<version>5.1.4</version>
</dependency>
</dependencies>
