Hi Jialin, > I come up a scenario: If a series receives a point of last year now, is the > series hot? Good scenario.
How about “order by latest” ? Since “LAST” is related to another function … Best, ----------------------------------- Zesong Sun School of Software, Tsinghua University 孙泽嵩 清华大学 软件学院 > 2020年6月10日 16:38，Jialin Qiao <[email protected]> 写道： > > Hi > > To show timeseries and display them by the descending order of the timestamp > of the last point. > > The new grammar is designed as "order by heat". > E.g., the last time of s1 is 10, the last time of s2 is 8. When order by > heat, the result will display as "s1, s2". > > I come up a scenario: If a series receives a point of last year now, is the > series hot? > > Or "order by last" ? > > Thanks, > -- > Jialin Qiao > School of Software, Tsinghua University > > 乔嘉林 > 清华大学 软件学院 > >> -----原始邮件----- >> 发件人: "田原" <[email protected]> >> 发送时间: 2020-06-10 15:41:42 (星期三) >> 收件人: [email protected] >> 抄送: >> 主题: I've submitted a PR for ISSUE-1281 >> >> Hi, >> >> I submitted a pr to add an order-by-heat feature in show time series syntax. >> >> >> PR: https://github.com/apache/incubator-iotdb/pull/1341 >> >> ISSUE-1281: https://github.com/apache/incubator-iotdb/issues/1281 >> >> >> Best, >> --------------- >> Yuan Tian >> >> >>> -----原始邮件----- >>> 发件人: "田原" <[email protected]> >>> 发送时间: 2020-06-10 15:29:16 (星期三) >>> 收件人: [email protected] >>> 抄送: >>> 主题: [ISSUE-1281] Show timeseries in descending ordered of last point time >>> >>> Hi, >>> >>> >>> I'm working on the >>> issue-1281(https://github.com/apache/incubator-iotdb/issues/1281). I plan >>> to add a sub clause in show timeseries syntax, like: >>> >>> >>> SHOW TIMESERIES prefixPath? showWhereClause? orderByHeatClause? limitClause? >>> >>> >>> The 'orderByHeatClause' is added to support this feature. The detailed >>> syntax is: >>> >>> >>> orderByHeatClause >>> : ORDER BY HEAT >>> ; >>> >>> >>> It's an optional clause, if user doesn't specify it. The action of 'show >>> timeseries' will just be like before, the result set is sorted by the >>> registered time of the time series. >>> >>> >>> If it is specified, firstly we will obtain all the satisfying timeseries as >>> before, then we will sort them by the last point's timestamp. That means if >>> the timeseries is inserted recently, it will be shown in the front. >>> >>> >>> In the implementation, as we have got the LeafMNode before, so we can use >>> the cachedLastValuePair field in it to get last timestamp, if the >>> cachedLastValuePair is null, we will construct a LastQueryPlan to get it. >>> >>> >>> Best, >>> --------------- >>> Yuan Tian
