dec memory cost

src/main/scala/com/aliyun/odps/spark/examples/makedata_recsys/video_dssm_sampler.scala

@@ -99,6 +99,7 @@ object video_dssm_sampler {
 
     try {
       logger.info(s"Starting negative sample generation for date: $dt")
+      spark.conf.set("spark.sql.autoBroadcastJoinThreshold", -1)
       val sc = spark.sparkContext
 
       // 2 读取odps+表信息