我必须创建管道来从BigQuery传输数据并将其保存为json文件。但我得到了这个错误。SQL查询的结果是3000万条记录。如何改进这段代码？
错误：
[error]（run-main-0）java.lang.OutOfMemoryError：Java堆空间[错误]

object tmp {
      private val logger = LoggerFactory.getLogger(this.getClass)
      var date = "2023-05-22"

      def main(cmdlineArgs: Array[String]){
        val (sc, args) = ContextAndArgs(cmdlineArgs)
        val file_path = "src/main/scala/thunder/tmp.sql"
        val sql_content = Source.fromFile(file_path).mkString
        val queryConfig = QueryJobConfiguration.newBuilder(sql_content).build()
        val client = BigQueryOptions.getDefaultInstance().getService()
        val queryResult = client.query(queryConfig)
        var result = queryResult.iterateAll().iterator().asScala.map(_.asScala.map(_.getValue).toArray).toSeq
        val json_result = result.map { row =>
          val pin_username = row(0).toString
          val feature_name = row(1).toString
          implicit val formats = DefaultFormats
          write(Map(("pin_username"->pin_username),("feature_name" -> feature_name)))

        }
        sc.parallelize(json_result)
          .saveAsTextFile("output", ".json")

        sc.close().waitUntilFinish()
    }
}