Hi, I also think 'order by latest' is better. What do you think, Qiao?
Best, --------------- Yuan Tian > -----原始邮件----- > 发件人: "孙泽嵩" <[email protected]> > 发送时间: 2020-06-10 18:07:09 (星期三) > 收件人: [email protected] > 抄送: > 主题: Re: I've submitted a PR for ISSUE-1281 > > 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 >
