Questions about data integrity in Kylin

[BELLIER Jean-luc <je...@rte-france.com>]

Hello,

I was wondering about a few things :

*         When I launch a query using filters on PART_DT (from the sample model), e.g. WHERE PART_DT='2013-12-31', I get a result through the Kylin web interface, whereas it gives me a mistake in Hive and Impala, indicating an unknown type on PART_DT. Does it mean that the data are not queried directly in Hive, but through a "copy".  This couls explain why the syntax "DEFAULT.<table name> does not work in the query editor.

*         What does happen when the Hive tables are populated ? Should I resynchronize the tables or not ?

*         How is the data integrity ensured ? As far as I can notice, there is no control on data through the model creation interface; this supposes that the data are initially well-formed. So how does Kylin manage this (input mistakes, ...) ?

Thank you in advance for your help. Have a good day.

Best regards,
Jean-Luc.


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Re: Questions about data integrity in Kylin

[Billy Liu <bi...@apache.org>]

Hi  BELLIER,

I suggest you reading some Kylin introduction document or slide. It
will explain how Kylin works, for example:
https://www.slideshare.net/XuJiang2/kylin-hadoop-olap-engine

With Warm regards

Billy Liu


2018-02-21 19:53 GMT+08:00 BELLIER Jean-luc <je...@rte-france.com>:
> Hello,
>
>
>
> I was wondering about a few things :
>
> ·         When I launch a query using filters on PART_DT (from the sample
> model), e.g. WHERE PART_DT=’2013-12-31’, I get a result through the Kylin
> web interface, whereas it gives me a mistake in Hive and Impala, indicating
> an unknown type on PART_DT. Does it mean that the data are not queried
> directly in Hive, but through a “copy”.  This couls explain why the syntax
> “DEFAULT.<table name> does not work in the query editor.
>
> ·         What does happen when the Hive tables are populated ? Should I
> resynchronize the tables or not ?
>
> ·         How is the data integrity ensured ? As far as I can notice, there
> is no control on data through the model creation interface; this supposes
> that the data are initially well-formed. So how does Kylin manage this
> (input mistakes, …) ?
>
>
>
> Thank you in advance for your help. Have a good day.
>
>
>
> Best regards,
>
> Jean-Luc.
>
>
>
> "Ce message est destiné exclusivement aux personnes ou entités auxquelles il
> est adressé et peut contenir des informations privilégiées ou
> confidentielles. Si vous avez reçu ce document par erreur, merci de nous
> l'indiquer par retour, de ne pas le transmettre et de procéder à sa
> destruction.
>
> This message is solely intended for the use of the individual or entity to
> which it is addressed and may contain information that is privileged or
> confidential. If you have received this communication by error, please
> notify us immediately by electronic mail, do not disclose it and delete the
> original message."