%sql explain(<join command>) Review the physical plan. If the broadcast join returnsBuildLeft, cache the left side table. If the broadcast join returnsBuildRight, cache the right side table. In Databricks Runtime 7.0 and above, set the join type toSortMergeJoinwith join hints enabled....
%sql explain(<join command>) Review the physical plan. If the broadcast join returnsBuildLeft, cache the left side table. If the broadcast join returnsBuildRight, cache the right side table. In Databricks Runtime 7.0 and above, set the join type toSortMergeJoinwith join hints enabled....
If you review the query plan,BroadcastNestedLoopJoinis the last possible fallback in this situation. It appears even after attempting to disable the broadcast. == Physical Plan == *(2) BroadcastNestedLoopJoin BuildRight, LeftAnti, ((id#2482L = id#2483L) || isnull((id#2482L = id#2...
其中plan.stats.sizeInBytes <= conf.autoBroadcastJoinThreshold 要求当表的大小小于conf.autoBroadcastJoinThreshold时它才可以被broadcast。conf.autoBroadcastJoinThreshold 对应 spark.sql.autoBroadcastJoinThreshold 参数。 是否选择BHJ、join的哪一边被广播综合决定于 join type (equi-join、哪一边是build side)和 joi...
4. Example of a Broadcast Join For our demo purpose, let us create two DataFrames of one large and one small using Databricks. Here we are creating the larger DataFrame from the dataset available in Databricks and a smaller one manually. ...
Therefore, it is important to carefully consider the partitioning strategy when using coalesce and broadcast join operations in Databricks, and to experiment with different partitioning strategies to find the optimal configuration for your specific use case. Hope this helps. Please let me know if any...
This article explains how to disable broadcast when the query plan has BroadcastNestedLoopJoin in the physical plan. You expect the broadcast to stop after
Broadcast Hash Join（BHJ）是SparkSQL用于分布式join操作的核心方法之一。在SQL中添加hint可指定使用BHJ实现join操作，但更多情况下，SparkSQL框架会自动选择是否采用BHJ。在Spark 3.0引入AQE特性后，BHJ的选择过程分为正常模式和AQE模式两个部分。在正常模式下，SQL解析过程涉及将优化后的逻辑计划转化为物理...
但即使我已经确定：***在mysql命令行下执行sql文件*** ***在mysql命令行下执行sql文件*** C:\Wind...
explain(<join command>) Review the physical plan. If the broadcast join returnsBuildLeft, cache the left side table. If the broadcast join returnsBuildRight, cache the right side table. In Databricks Runtime 7.0 and above, set the join type toSortMergeJoinwith join hints enabled....