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
