Kylin will pick up* foreign key* of lookup table,and* dimension column* as
rowkey by default.
and also add these items to aggregation group ,each group has *10 items* at
most
one relative hierarchy columns are treat as one item in aggregation group .
e.g.
We have fact table TEST_FACT with dmensions *a,b,c,d,e,f,g* primary key on
fact table is *id*
and lookup table TEST_LOOKUP with dimensions *h,i,j,k*
the rowkey item will contain *a,b,c,d,e,f,g,h,i,j,k,id*
and aggregation groups will be like:
group 1:
a,b,c,d,e,f,g,id,h,i
group 2:
j,k
the auto generate group may not be the best,so you need to adjust depends
on your own business logic.
On Tue, Mar 31, 2015 at 2:35 PM, Abhishek Sinha <[email protected]>
wrote:
> Thanks. Good explanation :)
>
> By default, Kylin picks up aggregation groups and rowkey automatically in
> the advanced setting. How is that done?
> Is aggregation group and rowkey connected?
>
> On Tue, Mar 31, 2015 at 11:55 AM, Shi, Shaofeng <[email protected]> wrote:
>
> > Aggregation groups is to reduce the cube calculation and storage; Lets
> see
> > a simple case:
> >
> > Say we have a cube has 6 dimensions:
> >
> > [A B C D E F] It will has 2^6 cuboids: 64;
> >
> > If your query pattern is: [group by A, B, C] or [group by D, E, F], then
> > you can split the 6 dimensions to two groups:
> > [A B C], [D E F];
> >
> > Then Kylin will skip some cuboid like AD, AE, Š;
> >
> > The total cuboid count will be 2^3 + 2^3 = 16, which is much less than
> the
> > original 64;
> >
> > On 3/31/15, 1:49 PM, "Abhishek Sinha" <[email protected]> wrote:
> >
> > >Went through the slide. Doesn't give much information about Advanced
> > >Settings.
> > >
> > >On Tue, Mar 31, 2015 at 9:01 AM, jason zhong <[email protected]>
> > >wrote:
> > >
> > >> Hi Abhishek,
> > >>
> > >> Aggregation Group is for cube optimization,
> > >>
> > >> Kylin will pick up dimension column and *fk on lookup table* as
> default
> > >> rowkey and aggregation group item.
> > >>
> > >> you can refer
> > >> http://www.slideshare.net/YangLi43/design-cube-in-apache-kylin
> > >> to know more about cube creation first.
> > >>
> > >> and for kylin architecture
> > >>
> > >>
> > >>
> > >>
> >
> http://www.slideshare.net/YangLi43/apache-kylin-deep-dive-2014-dec?next_s
> > >>lideshow=1
> > >>
> > >>
> > >>
> > >> On Mon, Mar 30, 2015 at 2:16 PM, Abhishek Sinha <
> [email protected]>
> > >> wrote:
> > >>
> > >> > Can someone explain the following while designing the cube in Kylin?
> > >> >
> > >> > 1. New Aggregation Groups
> > >> > 2. New RowKey Column
> > >> >
> > >> > By default, Kylin automatically picks up the some values for RowKey
> > >>and
> > >> > Aggregation groups in Advanced Settings Page.
> > >> > a) How is that done?
> > >> > b) When do we need add our own Aggregation Groups and RowKey?
> > >> > c) How is RowKey related to Aggregation Groups?
> > >> > d) What does length, dictionary and mandatory indicate?
> > >> >
> > >> > --
> > >> > Abhishek Sinha
> > >> > Mobile: +919035191078
> > >> > infoworks.io
> > >> >
> > >>
> > >
> > >
> > >
> > >--
> > >Abhishek Sinha
> > >Mobile: +919035191078
> > >infoworks.io
> >
> >
>
>
> --
> Abhishek Sinha
> Mobile: +919035191078
> infoworks.io
>
