Order by condition for data having same timestamp

[akshah1997]

Hello,

We are trying to find the last message for each time interval (lets say per minute) for a particular stream.

Given that there are multiple messages having same timestamps, we want to select just one message based on some conditions and not based on when it was added to the stream.
Can you please guide/advise us on how to proceed?

Thanks.

[alex-karpovich]

Greetings, @akshah1997

You can try to use QQL, we have special aggregates:
https://kb.timebase.info/community/development/qql/QQL%205.5/qql-tut-functions#stateful-functions

useful functions: OVER time(interval)

or you can provide more details about your stream schema, so I can try to help with query

[alex-karpovich]

I think the only way is to create a 'custom' aggregate function that can be used in QQL.
'custom' means implement some kind of java 'plugin' and use it with timebase server classpath
Let me check tomorrow if this is possible with Community Edition

[akshah1997]

Okay sure, thanks.

[akshah1997]

Hi @alex-karpovich, any updates please?
Thanks.

[ankitsoin]

So currently i have found easy workaround for same as in my case data is NOT real time.
I have loaded the data in the specific way of priority i need it so when TimeBase picks the last record over 1 minute it gives same record what i needed.

But if I get to know how to use custom aggregator as @alex-karpovich mentioned above, i can use it for other complex logics which I may require while retrieving data.
Thanks

[alex-karpovich]

https://github.com/finos/TimeBase-CE/blob/main-6.1/java/timebase/computations-std/src/main/java/com/epam/deltix/computations/finanalysis/BollingerBands.java

here is sample of custom function, full description is here

https://kb.timebase.info/community/development/qql/QQL%205.5/qql-tut-functions

you need to create own java library based on "computations-api" and add to the Timebase classpath
I will provide short instructions