tree b0ddd21ef9b89d22cfee5ea6a28156746400fda8
parent 23950ecd5f3c0f57d096639ff4185655aeec6df7
author yuxiaoyu <yuxiaoyu@bytedance.com> 1581423353 +0800
committer wankunde <wankunde@163.com> 1581423353 +0800

optimize get metric maps in 'MetricWriteStep'

**Why/What changes？**
In 'MetricWriteStep.getMetricMaps()' the dataframe was transformed to json rdd, and then collect, and then transformed to Seq[Map].
It's not elegant and hard to understand. More optimized way is to collect it first, and then transform it to Seq[Map] directly.

We have test it with our DQ cases. It works well.

Author: yuxiaoyu <yuxiaoyu@bytedance.com>

Closes #566 from XiaoyuBD/optimizeMetricWriteGetMaps.