BTW, only when derived column exist will add foreign key to rowkey and aggregation group.
On Tue, Mar 31, 2015 at 5:11 PM, jason zhong <[email protected]> wrote: > 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 >> > >
