By the way, some pictures of docs for 1.5 is still v.1.3 like "Getting Started -> Technical Concepts".
Could u explain Agg Group 's meaning concisely even though there's context of 'Each aggregation group is subset of dimensions, and build cuboid with combinations inside. It aims at pruning for optimization" to explain on the docs. But I still don't understand what the pruning for optimization mean or what's this setting's advantage. In my mind , when build cuboid, if I don't define any dims in advanced setting, it will build all cuboids, if I define any of hierarchy or mantory or joint dimension, it will prune the cuboids which do not include those dims defined in advanced setting. Is my understand for agg group right ? 2016-05-10 15:47 GMT+08:00 Mars J <[email protected]>: > Yes, Luke Han's idea of some auto-gen stuff for Agg Group is what I > thinking about. But the auto-gen maybe difficult to define. > In v1.3, it can create hierarchy dimensions by users themselves, users are > very clear to know how the hierarchy-relations between various columns. > Maybe u can auto-gen it first, and allow users to customize it. > > 2016-05-10 15:01 GMT+08:00 Luke Han <[email protected]>: > >> I think Mars' concern is right, we shouldn't introduce too complex >> concept for users. >> >> As most of BI/DW experts, they are familiar to create dimension with >> different types: normal, hierarchy, derived... >> >> The "Aggregation Group" is in Advanced setting which should not open to >> Users (Modeler) directly. >> >> We should move back "hierarchy" to previous place and do some auto-gen >> stuff for Agg Group. >> >> Thanks. >> >> >> >> >> Best Regards! >> --------------------- >> >> Luke Han >> >> On Mon, May 9, 2016 at 11:15 PM, Mars J <[email protected]> wrote: >> >>> what's difference between pre-aggregation and post-aggregation ? >>> I have no experience in traditional BI and OLAP, not so clear to this >>> concept. >>> >>> 2016-05-10 13:51 GMT+08:00 ShaoFeng Shi <[email protected]>: >>> >>>> This is easy in my mind; Firstly you need understand the "derived" >>>> dimension; "Derived" dimensions can only be from lookup table, they will >>>> be derived from the pk/fk column at runtime; only the FK column will be >>>> built into cube; So if you use "derived", you don't need, and have no >>>> chance to declare them as hierarchy; >>>> >>>> Whether define them as a "derived" or "normal" + "hierarchy", depends >>>> on how you balance the pre-aggregation and post-aggregation. >>>> >>>> >>>> >>>> >>>> 2016-05-10 11:45 GMT+08:00 Mars J <[email protected]>: >>>> >>>>> It's very confused if I want to define a hierachy dim, I need to >>>>> define it be normal or derived and then add it to aggregation group for >>>>> hierachy dims. if this hierachy dims I want to define includes 3 columns, >>>>> it will be 3 dims if define it in normal dims or 1 dim if define it in >>>>> derived dims. So how to handle it ? >>>>> >>>>> 2016-05-10 10:53 GMT+08:00 Mars J <[email protected]>: >>>>> >>>>>> Hi, >>>>>> There is something confused me . In kylin 1.3 ,the dimension >>>>>> types are hierachy/derived/normal and mantory when create a cube in the >>>>>> dimensions step. In kylin 1.5.1 there 2 types including normal and >>>>>> derived >>>>>> in the dimensions step, and in the advanced setting , aggregation group >>>>>> has >>>>>> some aggregating manner of hierachy/mantory/joint. >>>>>> >>>>>> I test 1.3 including 2 derived dims and 2 hierachy dims(also has >>>>>> 3 columns each dims, level1-> level2 -> level3), I said it has 4 dims in >>>>>> the traditional BI way, but in kylin ,it's 10 dims. >>>>>> In kylin 1.5.1, I can't create hierachy dims directly, but I can >>>>>> create it for derived dims or normal dims first, then in the aggregroup , >>>>>> make it to hierachy dims. but I don't know how to count it in traditional >>>>>> BI way. >>>>>> >>>>>> We can discuss about the dims, and the different dims definition. >>>>>> >>>>> >>>>> >>>> >>>> >>>> -- >>>> Best regards, >>>> >>>> Shaofeng Shi >>>> >>>> >>> >> >
