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Posted to dev@iotdb.apache.org by 周钰坤 <zy...@gmail.com> on 2021/07/24 02:07:30 UTC
Measurement Template New Constraints
Hi,
Apache IoTDB supports Measurement Template feature from version 0.13.
The current version allows user to set different templates to different
nodes of a path and the nearest template to current node will be valid.
This will result in schema and data lost while user set a new template,
which doesn't contain schemas in the existing upper template.
Therefore, a new constraint will be introduced. If a template has been
set to a node, it will be forbidden to set any template to the ancestors or
descendants of this node, like the constraint of storage group.
Thanks,
Yukun Zhou
Re: Measurement Template New Constraints
Posted by 周钰坤 <zy...@gmail.com>.
As far as I know, the user interface of template has been discussed and
defined in this doc, 一元/多元时间序列与模式模板用户手册 (shimo.im)
<https://shimo.im/docs/eME9YgS50wIqhOiO>, but the current implementation
only support Session.
The UI of "assign of template" has already been defined. The UI of
"unassign of template" operation need further discussion and definition.
The implementation of the whole eature needs more work on related modules.
The mentioned constraint in upper mail could be added and implemented to
current metadata module first.
—————————————————
Yukun Zhou
School of Software, Tsinghua University
Xiangdong Huang <sa...@gmail.com> 于2021年7月26日周一 下午4:37写道：
> "How to assign and unassign a template to a node" should be defined clearly
> before implementation.
>
> -----------------------------------
> Xiangdong Huang
> School of Software, Tsinghua University
>
> 黄向东
> 清华大学 软件学院
>
>
> Jialin Qiao <qi...@apache.org> 于2021年7月24日周六 下午2:40写道：
>
> > +1
> > —————————————————
> > Jialin Qiao
> > School of Software, Tsinghua University
> >
> > 乔嘉林
> > 清华大学 软件学院
> >
> >
> > 周钰坤 <zy...@gmail.com> 于2021年7月24日周六 上午10:07写道：
> >
> > > Hi,
> > >
> > > Apache IoTDB supports Measurement Template feature from version
> 0.13.
> > > The current version allows user to set different templates to different
> > > nodes of a path and the nearest template to current node will be valid.
> > > This will result in schema and data lost while user set a new
> > template,
> > > which doesn't contain schemas in the existing upper template.
> > > Therefore, a new constraint will be introduced. If a template has
> > been
> > > set to a node, it will be forbidden to set any template to the
> ancestors
> > or
> > > descendants of this node, like the constraint of storage group.
> > >
> > > Thanks,
> > > Yukun Zhou
> > >
> >
>
Re: Measurement Template New Constraints
Posted by Xiangdong Huang <sa...@gmail.com>.
"How to assign and unassign a template to a node" should be defined clearly
before implementation.
-----------------------------------
Xiangdong Huang
School of Software, Tsinghua University
黄向东
清华大学 软件学院
Jialin Qiao <qi...@apache.org> 于2021年7月24日周六 下午2:40写道：
> +1
> —————————————————
> Jialin Qiao
> School of Software, Tsinghua University
>
> 乔嘉林
> 清华大学 软件学院
>
>
> 周钰坤 <zy...@gmail.com> 于2021年7月24日周六 上午10:07写道：
>
> > Hi,
> >
> > Apache IoTDB supports Measurement Template feature from version 0.13.
> > The current version allows user to set different templates to different
> > nodes of a path and the nearest template to current node will be valid.
> > This will result in schema and data lost while user set a new
> template,
> > which doesn't contain schemas in the existing upper template.
> > Therefore, a new constraint will be introduced. If a template has
> been
> > set to a node, it will be forbidden to set any template to the ancestors
> or
> > descendants of this node, like the constraint of storage group.
> >
> > Thanks,
> > Yukun Zhou
> >
>
Re: Measurement Template New Constraints
Posted by Jialin Qiao <qi...@apache.org>.
+1
—————————————————
Jialin Qiao
School of Software, Tsinghua University
乔嘉林
清华大学 软件学院
周钰坤 <zy...@gmail.com> 于2021年7月24日周六 上午10:07写道：
> Hi,
>
> Apache IoTDB supports Measurement Template feature from version 0.13.
> The current version allows user to set different templates to different
> nodes of a path and the nearest template to current node will be valid.
> This will result in schema and data lost while user set a new template,
> which doesn't contain schemas in the existing upper template.
> Therefore, a new constraint will be introduced. If a template has been
> set to a node, it will be forbidden to set any template to the ancestors or
> descendants of this node, like the constraint of storage group.
>
> Thanks,
> Yukun Zhou
>