I have 2 fact tables. One is being used as a dimension - Bridge table for multi valued Dimensions. The other is FactSales. What I am trying to achieve is to get a count of customers from sales table where they have a specific member property (comes from the other Fact Table). I thought making the relationship between the two is the way ahead.
I tried using the PersonID as the join in Dimension Usage tab, trying both regular and References (using DimPerson) but it didn't work. Does anyone know why this might be? Or what is the way around this?
Related
I am modelling cube in SSAS. Cube has around 20 dimensions and 6 fact tables. Some of the dimensions are common among the fact tables. e.g. Time dimension. Fact_PNL has 3 date columns for those we have 3 role playing dimensions in the dimension usages.Another fact table has 5 date columns for them as well we have separate role playing dimensions in dimension usage tab. We have a common dimension Company which is foreign key in all fact tables. We might need to combine the data from multiple facts to get final output.
Should i create 6 role playing dimension for each of the fact table or use the same dimension for all fact tables?
Role playing dimensions should be created when we have multiple columns pointing to the same dimension ?
It's up to you. If the role playing dimension plays the same logical role for each fact table, then I would use the same RPD for the same logical role in each fact table. But if you want to use separate ones for each fact table, maybe because you think in the future they might be used differently, then you can.
In short, either way works fine, so whatever makes the most intuitive sense to you and other users is the way you should go.
Yes, that is the purpose of Role Playing Dimensions. When two or more columns in the same fact table reference the same dimension.
We are having a very frustrating problem with SSAS. we are trying to create a fairly simple Tabular model have had no problem with a few dimensions and a single fact table. when we recently added a new dimension table, and a second fact table we can not get it to stop telling us that
The relationship cannot be created because each column contains duplicate values.
we have deleted and reimported these tables many times. at times we can attach the Dim table to an existing fact without problem, which tells me that the key is unique, but then it errors when attaching to a second fact. at other times it just errors right away.
The key and Foreign Key values are Int in the database. and we have examined the data many times, creating stripped down tables with just a few columns, validating that a
Select Distinct ID from Table
type query returns the same number of rows as a wide open one.
At this point it looks like we simply have a bug in SSAS Tab. I cant see a good reason for this to not work.
any ideas would be greatly appreciated
I have had the same problem, the way I solved is to create the relationship in reverse order meaning: from the 1 to many. This will solve the issue, and the relationship's direction will indeed be from the many to the 1
I do not have any explanation for this...
sometimes SSAS cannot detect that your column is unique so you should do that. you can click on your primary key column and get properties and choose true on the unique property and after that create your relationship
I have a cube with 3 fact tables and 20 + dimensions that relate easily to all 3 fact tables and everything works fine except for the fact that one of the dimensions (Warehouse) is only related to 2 of the 3 fact tables. My problem I guess is a display issue. When the user is viewing measures from all 3 fact tables then drags over the Warehouse dimension, it simply repeats the grand total of the measure in the 3rd fact table for every possible value of Warehouse. This certainly makes sense to me as there is no relationship set up and it's conceptually behaving almost like a cross-join. Nonetheless, it's confusing to users and I'd like to not have the grand total duplicated for each dimension member in Warehouse. I was thinking one solution was to create a dummy warehouse called "Not Applicable" and then relate every row in the 3rd fact table to that dimension member. I was hoping there's just a setting in SSAS where I could control this behavior so I didn't have to create any new warehouse values. Is there a standard way to handle non-related dimensions with multiple fact tables? Thanks in advance.
You can use the "IgnoreUnrelatedDimensions" property of the measure group not related to Warehouse: set it from the default value true to false. Then, measure values for this measure group will only be shown for the "All" members from the warehouse dimension, and the cells will be null (empty) for non-All members of this dimension.
This is a global setting per measure group, you cannot configure it individually per dimension and measure group. But for your purpose, this should be fine.
I have three tables, one fact and two dimensions. I want to make a referenced relationship between the fact table(measures) called InternetSales and the Geography table, se image(schemaCubeStructure".
The intermediate table is Customer. I first create the Geography and InternetSales tables and then the Customer with a field from Geography to use later when creating the ref. rel.
Everything works fine until browsing the data in the cube (se image "errorBrowseSalesCube". If i don´t make the relationship between the two tables i get image "correctBrowseSalesCube" which is what i want. That is i don´t get any data when processing with the rel.ref.
See image "dimensionUsageSalesCube for rel.ref.
Why is that i don´t get any data?
correctBrowseSalesCube
errorBrowseSalesCube
dimensionUsageSalesCube
schemaCubeStructure
What fields did you use when setting up your reference dimension relationship between Georgaphy and Internet Sales?
The in the AdventureWorksDW database, the Georgaphy dimension is a snowflake off of Customer dimension. In the AdvWrks cube project, Microsoft includes the geography table and corresponding attributes in the customer ssas dimension (red boxes in screenshot below). However, they could have, as it looks like you are trying to do, simply added the GeographyKey to the customer dimension (red arrow in screenshot below)
This exposes the GeorgaphyKey field when creating the reference dimension relationship so that you can properly define the relationship between the intermediate dimension (customer) and the reference dimension (geography):
After that, you can properly browse the Internet Sales facts by Georgraphy dimension attribute (and user) hierarchies:
The correctBrowse sales cube can be easily explained. It means that the data is not calculated based on the Geography dimension and thus indicates that the connection between the Internet sales and the Geography is not correctly calculated.
I would suggest the following:
Try making the customer a Mesaure (or fact table). Do not rename it just make a measure i.e. the count of customers (can be used as a counter of customers/per region or can be invisible altogether).
Then The customer will appear as a measure in Dimension usage and then connect Geography to Internet sales via a many to many relation Using the customer measure table.
I have designed a relatively simple data warehouse that uses the star schema. I have a fact table with just a primary key along with CompanyID and Amount (the actual measurement) columns. Of course I also have a dimension table to represent the companies which the fact table references.
Now I'm required to create a single level hierarchy (CompanyGroup) for companies. This seems like an easy task but the catch is that a single company should be allowed to exist within multiple CompanyGroups.
I experimented with this by creating a new dimension table called CompanyHierarchy that holds a primary key, GroupKey and CompanyKey. Defining a user defined hierarchy where GroupKey is the top level and CompanyKey is the second level yields A duplicate attribute key has been found error for the CompanyKey attribute while processing the dimension.
So, I'm not quite sure how to even start with this. How can I create a user defined hierarchy within a dimension where attributes can exist multiple times?
Screen shot of my current cube definition can be seen at:
img132.imageshack.us/img132/6729/ssasm2m.gif
You need to create a many-to-many relationship (one company can belong to many groups and one group can have many companies) There is an example of a many-to-many relationship in the Adventure Works cube around the sales reason dimension and there is an extensive white paper here that explains a number of different ways of using many-to-many relationships.
There is also a technique for supporting multiple members in the one hierarchy that I documented here