[2/2] spark git commit: [SPARK-9646] [SQL] Add metrics for all join and aggregate operators

[SPARK-9646] [SQL] Add metrics for all join and aggregate operators This PR added metrics for all join and aggregate operators. However, I found the metrics may be confusing in the following two case: 1. The iterator is not totally consumed and the metric values will be less. 2. Recreating the

[2/2] spark git commit: [SPARK-9646] [SQL] Add metrics for all join and aggregate operators

[SPARK-9646] [SQL] Add metrics for all join and aggregate operators This PR added metrics for all join and aggregate operators. However, I found the metrics may be confusing in the following two case: 1. The iterator is not totally consumed and the metric values will be less. 2. Recreating the