df.write.jdbc是否处理JDBC池连接？

Question

Do you know if the following line can handle jdbc pool connection: 您是否知道以下行是否可以处理jdbc池连接：

df.write
  .mode("append")
  .jdbc(url, table, prop)

Do you have any idea? 你有什么主意吗？ Thanks 谢谢

Answer 1

I don't think so. 我不这么认为。

spark.read.jdbc requests Spark SQL to create a JDBCRelation . spark.read.jdbc请求Spark SQL创建JDBCRelation 。 Eventually buildScan is executed that in turn calls JDBCRDD.scanTable that leads to JdbcUtils.createConnectionFactory(options) for JDBCRDD . 最终buildScan被执行依次调用JDBCRDD.scanTable导致JdbcUtils.createConnectionFactory（期权）为JDBCRDD 。

With that, you see driver.connect(options.url, options.asConnectionProperties) and unless driver deals with connection pooling Spark SQL does not do it. 这样，您将看到driver.connect（options.url，options.asConnectionProperties），除非driver处理连接池，否则Spark SQL不会执行。

(just noticed that you asked another question) （只是注意到您问了另一个问题）

df.write.jdbc is similar. df.write.jdbc与此类似。 It leads to JDBCRelation again that uses the same RDD. 它再次导致使用相同RDD的JDBCRelation 。