Re: Inquiry Regarding Key Column Creation for IoTDB

[Yuan Tian]

Hi Trevor,

Now there is no `group by device` in IoTDB, what you want may be the
`align by device` clause.

Best regards,
---
Yuan Tian


On Fri, Feb 16, 2024 at 5:48 AM Trevor Hart  wrote:

> Would it not be better to utilise the hierarchy in IoTDB? This saves space
> and means no need for a key
>
>
>
> So
>
>
>
> root.vehicles.CAR1
>
> root.vehicles.CAR2
>
> root.vehicles.CAR3
>
>
>
> And then under each CAR store lat, long, speed etc
>
>
>
> You can still query all of the data
>
>
>
> select * from root.vehicles.*
> limit 1000
> group by device
>
>
>
> That way the key is part of the schema and not a measurement.
>
>
> I use a similar model for storing server metrics (CPU, RAM, DISK etc)
>
>
>
> Thanks
>
>
>
>
>  On Tue, 16 Jan 2024 22:09:19 +1300 Xiangdong Huang <
> saint...@gmail.com> wrote ---
>
>
>
> Hi Cheongu Kim,
>
> Please send email to mailto:dev@iotdb.apache.org for discussion (remember
> to
> subscribe the mailing list first).
>
> As for your question, maybe the easiest method is add an offset on the
> timestamp to make they different.
> e.g.,
> origin data: , ,
>  
> to:
> , ,   1705396049000, 2.2>
>
> Best,
> ---
> Xiangdong Huang
> School of Software, Tsinghua University
>
>
> 김천구  于2024年1月16日周二 02:33写道：
>
> >
> > Dear Apache IoTDB Development Team
> >
> > Greetings, I hope this email finds you well. My name is Cheongu Kim and
> I am reaching out to you today to request some assistance. I currently plan
> to test IoTDB with some spatio-temporal(so-called ST) dataset which
> consists of time, longitude, latitude, and serial data generated from these
> 3 elements.
> >
> > Since the data is about trajectories of vehicles, there are hundreds of
> duplicates at the same time even in one vehicle because of its measurement
> method. And the dataset can be identified by the serial data(Since space
> and time are unique)
> >
> > I need to make a database which can be identified by the serial data,
> Which means the serial data must be a key column or at least make sure not
> to lose the data because it has the same time value or timestamp.
> >
> > I read about IoTDB papers, and explored the website but was unable to
> find the information about creating the key column or unique column. I know
> it's a time series database so time is the key column but how can I make
> another key or unique column in iotdb?
> >
> > Thank you in advance for your time and assistance. I look forward to any
> insights or information you can provide.
> >
> > Sincerely,
> >
> > Cheongu Kim
> > mailto:ckim191...@gmail.com

Re: Inquiry Regarding Key Column Creation for IoTDB

[Trevor Hart]

Would it not be better to utilise the hierarchy in IoTDB? This saves space and 
means no need for a key



So



root.vehicles.CAR1

root.vehicles.CAR2

root.vehicles.CAR3



And then under each CAR store lat, long, speed etc



You can still query all of the data 



select * from root.vehicles.*
limit 1000
group by device



That way the key is part of the schema and not a measurement.


I use a similar model for storing server metrics (CPU, RAM, DISK etc)



Thanks 




 On Tue, 16 Jan 2024 22:09:19 +1300 Xiangdong Huang  
wrote ---



Hi Cheongu Kim, 
 
Please send email to mailto:dev@iotdb.apache.org for discussion (remember to 
subscribe the mailing list first). 
 
As for your question, maybe the easiest method is add an offset on the 
timestamp to make they different. 
e.g., 
origin data: , , 
  
to: 
, ,   
 
Best, 
--- 
Xiangdong Huang 
School of Software, Tsinghua University 
 
 
김천구  于2024年1月16日周二 02:33写道： 
 
> 
> Dear Apache IoTDB Development Team 
> 
> Greetings, I hope this email finds you well. My name is Cheongu Kim and I am 
> reaching out to you today to request some assistance. I currently plan to 
> test IoTDB with some spatio-temporal(so-called ST) dataset which consists of 
> time, longitude, latitude, and serial data generated from these 3 elements. 
> 
> Since the data is about trajectories of vehicles, there are hundreds of 
> duplicates at the same time even in one vehicle because of its measurement 
> method. And the dataset can be identified by the serial data(Since space and 
> time are unique) 
> 
> I need to make a database which can be identified by the serial data, Which 
> means the serial data must be a key column or at least make sure not to lose 
> the data because it has the same time value or timestamp. 
> 
> I read about IoTDB papers, and explored the website but was unable to find 
> the information about creating the key column or unique column. I know it's a 
> time series database so time is the key column but how can I make another key 
> or unique column in iotdb? 
> 
> Thank you in advance for your time and assistance. I look forward to any 
> insights or information you can provide. 
> 
> Sincerely, 
> 
> Cheongu Kim 
> mailto:ckim191...@gmail.com

Re: Inquiry Regarding Key Column Creation for IoTDB

[Xiangdong Huang]

Hi Cheongu Kim,

Please send email to dev@iotdb.apache.org for discussion (remember to
subscribe the mailing list first).

As for your question, maybe the easiest method is add an offset on the
timestamp to make they different.
e.g.,
origin data: , ,
 
to:
, ,  

Best,
---
Xiangdong Huang
School of Software, Tsinghua University


김천구  于2024年1月16日周二 02:33写道：

>
> Dear Apache IoTDB Development Team
>
> Greetings, I hope this email finds you well. My name is Cheongu Kim and I am 
> reaching out to you today to request some assistance. I currently plan to 
> test IoTDB with some spatio-temporal(so-called ST) dataset which consists of 
> time, longitude, latitude, and serial data generated from these 3 elements.
>
> Since the data is about trajectories of vehicles, there are hundreds of 
> duplicates at the same time even in one vehicle because of its measurement 
> method. And the dataset can be identified by the serial data(Since space and 
> time are unique)
>
> I need to make a database which can be identified by the serial data, Which 
> means the serial data must be a key column or at least make sure not to lose 
> the data because it has the same time value or timestamp.
>
> I read about IoTDB papers, and explored the website but was unable to find 
> the information about creating the key column or unique column. I know it's a 
> time series database so time is the key column but how can I make another key 
> or unique column in iotdb?
>
> Thank you in advance for your time and assistance. I look forward to any 
> insights or information you can provide.
>
> Sincerely,
>
> Cheongu Kim
> ckim191...@gmail.com