Hi kang-sen:
I do some test about Q1, {D1 to D10} have been included in an aggregation
group and {D1 to D9} have been added into mandatory dimension. Then kylin only
generates Cuboid {D1 to D10}(base Cuboid) which I expect {D1 to D10} and {D1 to
D9}. When I add {D1 to D8} in to mandatory dimension, kylin generates Cuboid
{D1 to D10}, {D1 to D8, D9} and {D1 to D8, D10} which I expect {D1 to D10}, {D1
to D8, D9}, {D1 to D8, D10} and {D1 to D8}. About your Q1, I think the answer
is ONLY ONE cuboid {D1 to D10} has been generated. But according the blog ("if
a dimension is specified as “mandatory”, then all of the combinations without
such dimension can be pruned"), the Cuboid {D1 to D9} should't been pruned.
Maybe someone else can give more detail.
Q2 is similar with this email
https://lists.apache.org/thread.html/3ccc8d7f98748d7c590c01c7da6ce666a16c4fe2b34be070940cae8f@%3Cuser.kylin.apache.org%3E
and jira https://issues.apache.org/jira/browse/KYLIN-2149 . Now kylin will
prevent config overlapping hierachy, mandatory and joint. Although the minds of
three aggregation rule are different and even contradictory, auto merging those
rules into Cuboids is feasible. For now, the restriction of aggregation group
can't realize your requirement which I think is common. May be the jira
KYLIN-2149 can be resolved in the future.
Best regards
yuzhang
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yuzhang
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[email protected]
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签名由网易邮箱大师定制
On 3/19/2019 23:09，Lu, Kang-Sen<[email protected]> wrote：
Hi, Yuzhang:
I would appreciate if you can provide answer to my 2 questions.
Thanks.
Kang-sen
From: Lu, Kang-Sen <[email protected]>
Sent: Friday, March 15, 2019 8:15 AM
To:[email protected]
Subject: RE: question related to the aggregation groups configuration
NOTICE: This email was received from an EXTERNAL sender
Hi, Yuzhang:
Thanks for taking time to reply.
I actually have read that article several times earlier before.
However, may be I missed some details or what, I am not clear about how those
rules actual work and how they interfere with each other.
From the article you pointed out, the hierarchy rule does have an example, so
it is less likely to be confused.
I did not find any discussion about the “mandatory rule”. It is supposed to be
very simple, but I am stuck by the details. Let’s say, “includes” is a set of
dim: { d1, d2, … d10}, and the “mandatory” is a set of dim: {D1, …, D9}.
So it is obvious that each cuboid generated from this agg group should all
include set of dim {D1, …, D9}.
Now, D10 could be either selected or not. So the natural guess is that this agg
group will generate two cuboids, i.e {D1,…,D9} and {D1,… D10}. Is this what
kylin will do?
Another detail I am not clear is the interaction of “joint rule” and the
“mandatory rule”. It seems that there is an interaction between these two
rules. I am not clear why, and it is not discussed in the article you mentioned.
That was my two original questions.
Thanks again.
Kang-sen
From: yuzhang <[email protected]>
Sent: Friday, March 15, 2019 7:46 AM
To:[email protected]
Subject: Re: question related to the aggregation groups configuration
NOTICE: This email was received from an EXTERNAL sender
Hi kang-sen:
Here is a blog about the mind of aggregation group. I hope it will help you.
https://kylin.apache.org/blog/2016/02/18/new-aggregation-group/
Best regards
yuzhang
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yuzhang
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[email protected]
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签名由 网易邮箱大师 定制
On 3/14/2019 21:21，Lu, Kang-Sen<[email protected]> wrote：
I am running kylin 2.5.1
I have two questions related to the aggregation group configuration. In the
kylin GUI, select “Model”, then try to edit a cube design, under “Grid”, select
“Advanced Setting”, we can enter multiple “Aggregation Groups”. Each
“Aggregation Group” can specify zero, one, or many cuboids, with the
combination of dimensions.
Q1: If I want one and only one cuboid to be created with dimensions set = {D1,
D2, … , D10}, then is it correct to enter D1-to-D10 in the “includes” list, and
“D1-to-D9 in the “Mandatory Dimensions” list? The key question is “will kylin
generate two cuboids, i.e. {D1, …, D9} and {D1, … , D10} or just one cuboid”?
Q2: If I entered D1-to-D10 into the “includes” list, and entered {D1, D2} in
the “Joint Dimensions” list, then I can’t enter either D1 or D2 into the
“Mandatory Dimensions” list? I was thinking if I entered {D1, D3, … , D9} in
the “Mandatory Dimensions”, and with {D1, D2} in the “Joint Dimensions”, then
there should only one cuboid generated for {D1, D2, …, D10}. Why is it not
allowed?
Maybe the doc have this information described. But it is not clear to me
exactly how does kylin process the info entered in the “includes”, “Mandatory
Dimensions”, and “Joint Dimensions”. Can someone either point me to some
document or answer the questions I mentioned above.
Thanks.
Kang-sen
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