If the count condition is dynamic then flag column won't help..
I'm not clear of your full requirement, but the below returns the count of
one condition quickly:
select count(*) from fact where condition_goes_here
You can invoke similar queries multiple times, or embed it as subqueries to
get what you want.
Cheers
Yang
On Tue, Mar 3, 2015 at 5:01 PM, Santoshakhilesh <[email protected]
> wrote:
> Hi Yang ,
> I could not understand your meaning correctly about sum(flag_column)
> For example following case , column1...column4 is part of my fact table ,
> so how should I map a flag column for coollowing case ?
> count(case when column1 < 5 or column2 < 5 or column3 < 80 or column4 < 15
> then 1 else 0 end)
>
> Yes subquery is one option but as you said , I will not able to take
> benifit of precalculated data.
>
> Actuall above is just one example , my queries can be dynmaic involving
> nested conditions using count , sum , max , min + , - <*,/ and / or
>
> Regards,
> Santosh Akhilesh
> Bangalore R&D
> HUAWEI TECHNOLOGIES CO.,LTD.
>
> www.huawei.com
>
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> ________________________________________
> From: Li Yang [[email protected]]
> Sent: Tuesday, March 03, 2015 1:37 PM
> To: [email protected]
> Subject: Re: Qury about Measures Formula
>
> Minor correction -- *subquery* should fulfill this case -- well, not
> necessarily subquery, just put the count(..) on select clause and it should
> work. However this kind of work is based on runtime calculation and does
> not benefit Kylin's pre-calculate ability.
>
> Having a flag column prepared on fact table is more preferable in terms of
> performance. Kylin will be able to pre-aggregate sum(flag_column) and your
> query at runtime will be lightening fast.
>
> Cheers
> Yang
>
> On Mon, Mar 2, 2015 at 8:47 PM, Luke Han <[email protected]> wrote:
>
> > subquery should fulfill this case. please have a try and let's know if
> > there's any issue.
> >
> > And, if this is just indicate, can you process it in ETL phase when
> create
> > Hive table?
> >
> > Thanks.
> >
> > Luke
> >
> >
> >
> > Best Regards!
> > ---------------------
> >
> > Luke Han
> >
> > 2015-03-02 20:16 GMT+08:00 Santoshakhilesh <[email protected]
> >:
> >
> > > Hi All ,
> > >
> > >
> > >
> > > While adding measures while making cube. The formulas supported are
> > > count , max , min , ...
> > >
> > >
> > >
> > > I have a case where the measure is simply not a count , max , min
> or
> > > sum
> > >
> > >
> > >
> > > I want to define based on the value of a column in fact table like
> > > below.
> > >
> > >
> > >
> > > count(case when column1 < 5 or column2 < 5 or column3 < 80 or
> column
> > <
> > > 15 then 1 else 0 end)
> > >
> > >
> > >
> > > How do I support such measures using kylin ? Is there a way to do
> > this
> > > ?
> > >
> > >
> > >
> > > Regards,
> > > Santosh Akhilesh
> > > Bangalore R&D
> > > HUAWEI TECHNOLOGIES CO.,LTD.
> > >
> > > www.huawei.com
> > >
> > >
> >
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> > > This e-mail and its attachments contain confidential information from
> > > HUAWEI, which
> > > is intended only for the person or entity whose address is listed
> above.
> > > Any use of the
> > > information contained herein in any way (including, but not limited to,
> > > total or partial
> > > disclosure, reproduction, or dissemination) by persons other than the
> > > intended
> > > recipient(s) is prohibited. If you receive this e-mail in error, please
> > > notify the sender by
> > > phone or email immediately and delete it!
> > >
> >
>
