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From ShaoFeng Shi <shaofeng...@apache.org>
Subject Re: Joint VS Derived
Date Fri, 01 Jul 2016 09:01:18 GMT
"joint" just tell Kylin to prune certain combinations; for example, "joint
AB" will prune all combinations that only has A or only has B; the order in
"joint" doesn't matter;

for case 3), it should not be allowed on Kylin's GUI, can you verify?



2016-07-01 14:47 GMT+08:00 Richard Calaba (Fishbowl) <rcalaba@fishbowl.com>:

> Ok, so AB are joined, if:
>
>
>
> 1)      *Both* A and B have to be specified in either in WHERE-clause or
> GROUP BY-clause ; or one in WHERE and the other in GROUP-BY
>
>
>
> 2)      The order of the Joint Dimension is or is NOT important ??? If AB
> is joint, then BA is also joint, right?
>
>
>
> Meaning "select ... group by B, A" or "select ... where B = xx group by
> A" is also valid for AB as joint-dimension ???
>
>
>
> 3)      If AB is joint and AC is joint:
>
> a.       It does NOT mean that ABC is necessarily joint group, right ???
>
> b.       Also BC doesn’t have to be joint, correct ??
>
>
>
> Thanx, Richard.
>
>
>
> *From:* ShaoFeng Shi [mailto:shaofengshi@apache.org]
> *Sent:* Thursday, June 30, 2016 7:45 PM
> *To:* user@kylin.apache.org
> *Subject:* Re: Joint VS Derived
>
>
>
> This slide has introduction on the Derived Dim:
> http://www.slideshare.net/YangLi43/design-cube-in-apache-kylin
>
>
>
> "Joint" is introduced since 1.5.1; Using "joint" to combine multiple
> dimensions into "one" ; Say if you have Dim A, B, C; among them AB are
> always appeared together, e.g, "select ... group by A, B" or "select ...
> where A = xx group by B"; in this case you can declare AB as "joint"; for
> Kylin it looks like a 2 dim cube: AB, C, the combinations are decreased
> from 2^3 to 2^2;
>
>
>
> 2016-06-30 6:56 GMT+08:00 Alberto Ramón <a.ramonportoles@gmail.com>:
>
> Hi
>
> I don't understand the difference between:
>
> - Joint Dim (from Dimension Step )
> - Derived Dim (from Advance Setings  Step)
>
> Some example ?  :)
>
>
>
>
>
> --
>
> Best regards,
>
>
>
> Shaofeng Shi
>
>
>
> No virus found in this message.
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>



-- 
Best regards,

Shaofeng Shi

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