Hi, The same question with Lei Rui. Show the codes is better.
----------------------------------- Xiangdong Huang School of Software, Tsinghua University 黄向东 清华大学 软件学院 Lei Rui <nezhaleg...@163.com> 于2019年9月11日周三 上午10:32写道： > Hi, > > > I am also confused about the "six times worse" when creating timeseries. > > > Could you propose a draft pull request to IoTDB so that we can have a look > at your code implementation? > > > Sincerely, > Lei Rui > On 9/11/2019 09:25，安彦哲<thss15_a...@163.com> wrote： > Hi, > > > > > I'm trying to solve [IoTDB-164]( > https://issues.apache.org/jira/projects/IOTDB/issues/IOTDB-164?filter=allopenissues). > To accomplish > > the task, I've modified the structure of MTree and replace Path(String) of > several Maps with ID(Long), including > > latestTimeForEachDevice and latestFlushedTimeForEachDevice in the > org.apache.iotdb.db.engine.storagegroup.StorageGroupProcessor.java > > memTableMap in the > org.apache.iotdb.db.engine.memtable.AbstractMemTable.java > > > > > Then, I've carried out a simple experiment: > > create 200,000 timeseries in the same storage group > > insert 10 tuples(<timestamp, value>) into each of timeseries > > > > > The result shows that > > Step 1: the original version costs 25138.8ms while the modified one costs > 177753ms. It concludes that the modified version > performs six times worse than the original version when creating > timeseries. > > Step 2: the original version costs 213662.8ms while the modified one costs > 194271.2ms. It concludes that the modified version > performs nine percent better than the original version when inserting > values. > > > > > In addition, we don't usually create too many timeseries, while insertion > is the most frequently used operation in IoTDB. I'm confused > > whether we should apply the modified version. If anyone knows more about > this topic, please inform me. > > > > > Best, > > --------------------------------------------------- > > Yanzhe An > > School of Software, Tsinghua University > > > > | | > 安彦哲 > | > | > thss15_a...@163.com > | > 签名由网易邮箱大师定制
