ds中的数据源是按照trades的分区去取的，写入呢又是按照TAQ的数据分区写入的，两个分区不一样的情况下，写入是会冲突的。建议统一append，calcOHLC的部分return tmp，不做append，然后mr最后的结果合并，一起写入。OHLC应该不大。
mr函数执行时报错<ChunkInTransaction>filepath '/User_cq_M1/t1/cQCC' has been owned by transaction 3062896 RefId: S00002
执行下图例子：
请问下用mr，跑一次之后再跑同样的代码，为啥会有这个问题：
mr(ds, calcOHLC{, feaName, tbHandle}, add) => 85 map call(s) failed. The error message for the first failed call is: <ChunkInTransaction>filepath '/User_cq_M1/t1/cQCC' has been owned by transaction 3062896 RefId: S00002