Is it possible to collapse several similar nodes of different branches in a hierarchical dimension? - mdx

Let's say i have the following hierarchy that i use as a dimension:
Root
A1
B11
B12
...
B1N
B1Special
A2
B21
B22
...
B2N
B2Special
...
AM
BM1
BM2
...
BMN
BMSpecial
Under each of the "B" nodes there are several more nodes at different levels. Each leaf of the hierarchy has a measure associated (SUM of some fact F).
Is it possible with MDX to have the SUM of all and only the items children of the "Special" nodes?

I have to assume you want to see the sum of all 'Special' nodes only once, at the root level. In other words, you want to see just one number in your results set.
Assuming the hierarchy detailed in your original question was called 'Bob', and you had another dimension called 'Kate', you might try this...
WITH MEMBER [Bob].[Only the special levels]
AS 'Aggregate(
Filter(
{[Bob].[Name of level which holds B members].members},
InStr(1, [Bob].CurrentMember.Name, "Special") > 0
)
)'
SELECT {[Kate].defaultMember} ON ROWS,
{[Measures].[Whever you want to see aggregated]} ON COLUMNS
FROM [Cube name]
WHERE ([Bob].[Only the special levels])
This creates a new, temporary, member in the Bob dimension, which is an aggregation of several other members in the Bob dimension. We start with all the members that sit in one particular level. The Filter chooses only those members which have the word "special" in their name.
Note that InStr is a VBA function which is supported by Microsoft SSAS. It returns zero if the chosen string is not found. Alternative string searching functions may be available in other flavours of MDX.
You then use this new member in your WHERE clause, and slap your other dimensions/measures wherever you want.

Related

How to concatenate hidden cube dimension and measure with an MDX query?

I have a cube with three (relevant) dimensions (quarter, element and qualifier). The measure of interest is score, which is numeric.
The qualifier dimension is sparse, i.e. for each unique combination of quarter and element, the measure score is reported only for one qualifier, for the other members of the qualifier dimension the measure score is blank. Which qualifier is 'active' entirely depends on the quarter and element.
I want to build a table with quarter members as columns and element members as rows. The cell values should be the concatenation of the score measure and the name of that qualifier member (string) for which the score at the relevant intersection of quarter, element and qualifier is not blank.
To make matters more complex, one of the member names of the qualifier needs to be replaced with blanks in the table. There are four distinct members, which should be renamed in the table as follows: the member names '+', '-', '' stay as they are, while the name 'No Qualifier' should become blank, i.e. ''.
Below is an example of the structure I would like to get (note that there should be no '+' or '-' in case the corresponding score is reported in either the qualifier members '' or 'No Qualifier'):
2021Q4
2020Q4
2019Q4
Element 1
3
2+
2
Element 2
1
1
1
Element 3
2
3
2+
Element 4
2-
2-
3
I suppose I would need to create a calculated member, but so far I only get the concatenation and replacement to work with the currentmember function if I include the qualifier dimension explicitly in either rows or columns, which however is not a feasible output structure. Also, changing the underlying cube is not possible (it is maintained by IT).
I am new to cubes and MDX and have already spent two days trying to figure this out by myself. Since this is a work project, I am starting to panic. Any help would really be appreciated!

MDX Result Count

I am a beginner in MDX queries. Can any one tell me how to get the record count that is a result of a MDX query?
The query is following:
select {[Measures].[Employee Department History Count],[Measures].[Rate]} on columns, Non Empty{{Filter([Shift].[Shift ID].[Shift ID].Members, ([Shift].[Shift ID].CurrentMember.name <> "1"))}*{[Employee].[Business Entity ID].[Business Entity ID].Members}} on rows from [Adventure Works2012].
I have tried various methods and I haven't really got a solution for that.
I assume you mean row count when you talk of "record count", as MDX does not know a concept of records, but the result shown from an MDX query is the space built by the tuples on the axes.
I see two possibilities to get the row count:
Just count the rows returned from your above query in the tool from which you call the MDX query.
If you want to count in MDX, then let's state what you want to have:
You want to know the number of members of the set of non empty combinations of [Shift ID]s and [Business Entity ID]s where the Shift ID is not "1" and at least one of the measures [Employee Department History Count] and [Rate] is not null.
To state that different: Let's call the tuples like above for which the first measure is not null "SET1", and the tuples like above for which teh second measure is not null "SET2". Then you you want to know the count of the the tuples which are contained in one of these sets (or in both).
To achieve this, we define these two sets and then a calculated menber (a new measure in our case) containing this calculation in its definition, and then use this calculated member in the select clause to show it:
WITH
SET SET1 AS
NonEmpty({{Filter([Shift].[Shift ID].[Shift ID].Members,
([Shift].[Shift ID].CurrentMember.name <> "1"))}
* {[Employee].[Business Entity ID].[Business Entity ID].Members}},
{[Measures].[Employee Department History Count])
SET SET2 AS
NonEmpty({{Filter([Shift].[Shift ID].[Shift ID].Members,
([Shift].[Shift ID].CurrentMember.name <> "1"))}
* {[Employee].[Business Entity ID].[Business Entity ID].Members}},
{[Measures].[Rate])
MEMBER [Measures].[MyCalculation] AS
COUNT(SET1 + SET 2)
SELECT [Measures].[MyCalculation] ON COLUMNS
FROM [Adventure Works2012]
Please note:
The sets SET1 and SET2 are not absolutely necessary, you could also put the whole calculation in one long and complicated definition of the MyCalculation measure, but splitting it up makes is easier to read. However, the definition of a new member is necessary, as in MDX you can only put members on axes (rows, columns, ...). These members can either already been defined in the cube, or you have to define them in the WITH clause of your query. There is no such thing as putting expressions/calculations on axes in MDX, only members.
The + for sets is a union which removes duplicates, hence this operation gives us the tuples which have an non empty value for at least one of the measures. Alternatively, you could have used the Union function equivalently to the +.
The Nonempty() I used in the definitions of the sets is the NonEmpty function, which is slightly different from the NON EMPTY keyword that you can use on the axes. We use one of the measures as second argument to this function in both set definitions.
I have currently no working SSAS installation available to test my statement, hence there might be a minor error or typo in my above statement, but the idea should work.

SSAS MDX Calculated Measure Based on Related Dimension Attribute Value

I have a measure [Measures].[myMeasure] that I would like to create several derivatives of based on the related attribute values.
e.g. if the related [Location].[City].[City].Value = "Austin" then I want the new calculated measure to return the value of [Measures].[myMeasure], otherwise, I want the new calculated measure to return 0.
Also, I need the measure to aggregate correctly meaning sum all of the leaf level values to create a total.
The below works at the leaf level or as long as the current member is set to Austin...
Create Member CurrentCube.[Measures].[NewMeasure] as
iif(
[Location].[City].currentmember = [Location].[City].&[Austin],
[Measures].[myMeasure],
0
);
This has 2 problems.
1 - I don't always have [Location].[City] in context.
2. When multiple cities are selected this return 0.
I'm looking for a solution that would work regardless of whether the related dimension is in context and will roll up by summing the atomic values based on a formula similar to above.
To add more context consider a transaction table with an amount field. I want to convert that amount into measures such as payments, deposits, return, etc... based on the related account.
I don't know the answer but just a couple of general helpers:
1 You should use IS rather than = when comparing to a member
2 You should use null rather than 0 - 0/NULL are effecitvely the same but using 0 will slow things up a lot as the calculation will be fired many more times. (this might help with the second section of your question)
Create Member CurrentCube.[Measures].[NewMeasure] as
iif(
[Location].[City].currentmember IS [Location].[City].&[Austin],
[Measures].[myMeasure],
NULL
);

Slow MDX Custom Distinct Count Formula

I have a question related to creating a (more efficient) custom Distinct Count Measure using MDX.
Background
My cube has several long many to many relationship chains between Facts and Dimensions and it is important for me to be able to track which members in certain Dimensions do and do not relate to other Dimensions. As such, I have created a "Not Related" record in each of my dimension tables and set those records' ID values to -1. Then in my intermediate mapping fact tables I use the -1 ID to connect to these "Not Related" records.
The issue arises when I try to run a normal out-of-the-box distinct count on any field where the -1 members are present. In the case that a -1 member exists, the distinct count measure will return a result of 1 more than the true answer.
To solve this issue I have written the following MDX:
CREATE MEMBER CURRENTCUBE.[Measures].[Provider DCount]
AS
//Oddly enough MDX seems to require that the PID (Provider ID) field be different from both the linking field and the user sliceable field.
SUM( [Providers].[PID Used For MDX].Children ,
//Don't count the 'No Related Record' item.
IIF( NOT([Providers].[PID Used For MDX].CURRENTMEMBER IS [Providers].[PID Used For MDX].&[-1])
//For some reason this seems to be necessary to calculate the Unknown Member correctly.
//The "Regular Provider DCount Measure" below is the out-of-the-box, non-MDX measure built off the same field, and is not shown in the final output.
AND [Measures].[Regular Provider DCount Measure] > 0 , 1 , NULL )
),
VISIBLE = 1 , DISPLAY_FOLDER = 'Distinct Count Measures' ;
The Issue
This MDX works and always shows the correct answer (yeah!), but it is EXTREMELY slow when users start pulling Pivot Tables with more than a few hundred cells that use this measure. For less than 100 cells, the results are nearly instantaneously. For a few thousand cells (which is not uncommon at all), the results could take up to an hour to resolve (uggghhh!).
Can anyone help show me how to write a more efficient MDX formula to accomplish this task? Your help would be GREATLY appreciated!!
Jon Oakdale
jonoakdale#hotmail.com
Jon
You can use predefined scope to nullify all unnecessary (-1) members and than create your measure.
SCOPE ([Providers].[PID Used For MDX].&[-1]
,[Measures].[Regular Provider DCount Measure]);
THIS = NULL;
END SCOPE;
CREATE MEMBER CURRENTCUBE.[Measures].[Provider DCount]
AS
SUM([Providers].[PID Used For MDX].Children
,[Measures].[Regular Provider DCount Measure]),
VISIBLE = 1;
By the way, I used in my tests [Providers].[PID Used For MDX].[All].Children construction since don't know, what is dimension / hierarchy / ALL-level in your case. It seems like [PID Used For MDX] is ALL-level and [Providers] is name of dimension and hierarchy, and HierarchyUniqueName is set to Hide.

How to correctly write an MDX expression for a set

I've got 2 dimension hierarchies:
1 [Hierarchy1].[CityOfBirth]
2 [Hierarchy2].[CityOfResidence]
Both these hierarchies contain same members - cities
How do I write an MDX expression for a set containing all possible combinations of both dimensions
([Hierarchy1].[CityOfBirth].Member, [Hierarchy2].[CityOfResidence].Member)
but excluding those tuples where
[Hierarchy1].[CityOfBirth].Member = [Hierarchy2].[CityOfResidence].Member
I.e. there shouldn't be tuples like (New York, New York) or (Chicago, Chicago) in the set.
Use Filter, and filter on the Name property of the members:
Filter(([Hierarchy1].[CityOfBirth].Members * [Hierarchy2].[CityOfResidence].Members)
as c,
c.Current.Item(0).Name <> c.Current.Item(1).Name
)
Just be aware that this may need some time to run, as filter iterates across the complete cross product.