Simple MDX Calculated Member - mdx

In my simple cube, I have a measure = \[Measure\].\[Salary\], I have also \[DimEmpployee\].\[EmployeeLastName\].\[Smith\]. I would like to create calculated measure, where I can display in Axis 0 two measures - \[Measure\].\[Salary\] and calculated measure \[Measure\].\[SmithsSalaries\], to compare difference between Smith's earnings vs Total Salary.
I would like to compare Measure.SmithSalaries with other measures accross all diemensions. Is it possible to create such a measure using SCOPE statement?
I was playing around SCOPE statements, but it was displaying results only if DimEmployee was selected. I am looking for something which is running in blocks to avoid performance issues.

I think you only need a simple calculated measure.
CREATE MEMBER CURRENTCUBE.[Measures].[SmithSalaries]
AS ([DimEmployee].[EmployeeLastName].[Smith], [Measures].[Salary]),
VISIBLE = 1 ;
After that you can combine that with you total salary for example to get a ratio.
CREATE MEMBER CURRENTCUBE.[Measures].[SmithSalaries Ratio]
AS DIVIDE(([DimEmployee].[EmployeeLastName].[Smith], [Measures].[Salary]),[Measures].[Salary])
VISIBLE = 1 ;
SCOPE allows you to have different behaviors when different combinations of Dimensions are into play, like returning a different calculation when the DimEmployee is selected but otherwise just return the normal calculation. Like a Very efficient IF condition to check what are in the Axis of this calculation.

Related

Create a Calculated Member to remove need to load pre calculated measure

I am trying to replicate the following sql statement into MDX so that I can create a calculated member in the cube using the base loaded members instead of having to calculate it outside the cube in the table and then loading it
SUM(CASE WHEN ((A.SALES_TYPE_CD = 1) AND (A.REG_SALES=0))
THEN A.WIN_SALES
ELSE 0
END) AS Z_SALES
I am currently loading SALES_TYPE_CD as a dimension and REG_SALES and WIN_SALES as measures.
I also have a few other dimensions in the cube but for simplicity, lets just say I have 2 other dimensions, LOCATION and ITEM
The dimension has LOCATION has 3 levels, "Region"->"District"->"Store", ordered from top to bottom level.
The dimension has ITEM has 3 levels, "CLASS"->"SUBCLASS"->"SKU", ordered from top to bottom level.
The dimension has SALES TYPE has 2 levels, "SALES_TYPE_GROUP"->"SALES_TYPE_CD", ordered from top to bottom level.
I know that I cannot create a simple calculated member in the cube which crossjoins the "SALES_TYPE" dimension with another dimension to get the answer I want.
I would think that it would be a more complicated MDX statement something like :
CREATE MEMBER CURRENTCUBE.[Measures].[Z_Sales]
AS 'sum(filter(crossjoin(leaves(), [Sales Type].[Sales Type].
[Sales_Type_CD].&[1]), [Measures].[REG_SALES]=0),[Measures].
[WIN_SALES])',
FORMAT_STRING = '#,#',
VISIBLE = 1 ;
But this does not seem to return the desired result.
What would be the proper MDX code to generate the desired result?
I did a bunch of testing with the data and I now know that there is no way I can get the right answer by using MDX alone in this scenario. Like "Greg" and "Tab" suggested, the only way would be to have reg sales as a dimension. Since this is a measure, that is out of the question because of the large number of possibilities for the value which has a data type of decimal (18,2)
Thanks for taking the time to answer the question.

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
);

MDX Query SUM PROD to do Weighted Average

I'm building a cube in MS BIDS. I need to create a calculated measure that returns the weighted-average of the rank value weighted by the number of searches. I want this value to be calculated at any level, no matter what dimensions have been applied to break-down the data.
I am trying to do something like the following:
I have one measure called [Rank Search Product] which I want to apply at the lowest level possible and then sum all values of it
IIf([Measures].[Searches] IS NOT NULL, [Measures].[Rank] * [Measures].[Searches], NULL)
And then my weighted average measure uses this:
IIf([Measures].[Rank Search Product] IS NOT NULL AND SUM([Measures].[Searches]) <> 0,
SUM([Measures].[Rank Search Product]) / SUM([Measures].[Searches]),
NULL)
I'm totally new to writing MDX queries and so this is all very confusing to me. The calculation should be
([Rank][0]*[Searches][0] + [Rank][1]*[Searches][1] + [Rank][2]*[Searches][2] ...)
/ SUM([searches])
I've also tried to follow what is explained in this link http://sqlblog.com/blogs/mosha/archive/2005/02/13/performance-of-aggregating-data-from-lower-levels-in-mdx.aspx
Currently loading my data into a pivot table in Excel is return #VALUE! for all calculations of my custom measures.
Please halp!
First of all, you would need an intermediate measure, lets say Rank times Searches, in the cube. The most efficient way to implement this would be to calculate it when processing the measure group. You would extend your fact table by a column e. g. in a view or add a named calculation in the data source view. The SQL expression for this column would be something like Searches * Rank. In the cube definition, you would set the aggregation function of this measure to Sum and make it invisible. Then just define your weighted average as
[Measures].[Rank times Searches] / [Measures].[Searches]
or, to avoid irritating results for zero/null values of searches:
IIf([Measures].[Searches] <> 0, [Measures].[Rank times Searches] / [Measures].[Searches], NULL)
Since Analysis Services 2012 SP1, you can abbreviate the latter to
Divide([Measures].[Rank times Searches], [Measures].[Searches], NULL)
Then the MDX engine will apply everything automatically across all dimensions for you.
In the second expression, the <> 0 test includes a <> null test, as in numerical contexts, NULL is evaluated as zero by MDX - in contrast to SQL.
Finally, as I interpret the link you have in your question, you could leave your measure Rank times Searches on SQL/Data Source View level to be anything, maybe just 0 or null, and would then add the following to your calculation script:
({[Measures].[Rank times Searches]}, Leaves()) = [Measures].[Rank] * [Measures].[Searches];
From my point of view, this solution is not as clear as to directly calculate the value as described above. I would also think it could be slower, at least if you use aggregations for some partitions in your cube.

SSAS 2012 Calculated Member for Percentage

Being an SSAS newbie, I was wondering if it's possible to create a calculated member that references an individual row's value as well as the aggregated value in order to create a percentage?
For example, if I have a fact table with ValueA, I'd like to create a calculate member that essentially performed:
[Measures].[ValueA] (for each row I've sliced the data by) / [Measures].[ValueA] (the total)
Also I'd like to keep the total as the sum of whatever's been filtered in the cube browser. I feel certain this must be possible but I'm clearly missing something.
You can use the Axis function. Her is an example:
WITH MEMBER [Measures].[Percentage] AS
[Measures].[ValueA] / (Axis(1).CurrenMember.Parent, [Measures].[ValueA])
SELECT {[Measures].[ValueA], [Measures].[Percentage]} ON 0,
'what you want' ON 1
FROM your cube
(You may need to add check in the calculated member expression)

Ignore associated NULL values in SSAS calculated member

I'm creating Analysis Services cubes in Visual Studio BIDS, and have a question about summing in calculated members.
The data has to do with commercial real estate transactions. I want to sum square feet of building space involved in sales transactions for each region. I'm going to use that result in a weighted average calculation. However, I only want to sum the square feet of transactions which have non-null values for the corresponding building capitalization rate (cap rate) member.
Here is a drill-down to Athens in the cube browser:
Note that Athens has 15 values for square feet, but only 5 values for cap rate, reflecting my relational data source as shown here:
So, I only want to sum the five square feet values that have associated cap rate values. Doing the math with the relational query result above you can see that this should result in a sum just over 900K, not the 2 million+ sum shown in the BIDS screenshot.
My attempt at this calculation:
sum(
descendants(
[Property].[Property by Region].CurrentMember,
[Property].[Property by Region].[Metro Area]
),
iif([Measures].[Cap Rate] is null or [Measures].[Sq Ft] is null, 0,
[Measures].[Sq Ft])
)
ends up including the square feet values that have no corresponding cap rates, so I still end up with a value in the 2 millions.
Why is my iff() clause not working as one would expect?
I was finally able to create the weighted average calculation using a combination of Named Calculations in the Data Source View (DSV) and a calculated member (in the cube script). First, I went to the DSV and added a named calculation called xWeightedCapRt with a formula as follows:
CASE WHEN CapRate IS Null THEN Null Else CapRate * SqFt END
In the cube, I then added xWeightedCapRt as a New Measure. I set its aggregation function to Sum and left its Visible property set to True temporarily.
I created an additional Named Calculation called "xSqFt", defined as:
CASE WHEN CapRate IS Null THEN Null Else SqFt END
and again created a corresponding measure.
On the Calculation tab (of the cube designer) I created a new calculated member, [WAvg Cap Rate by Sq Ft], with the following formula:
[Measures].[x Weighted Cap Rt] / [Measures].[x Sq Ft]
After deploying and processing the cube, I was able to verify that the weighted average calculation matched my spreadsheet numbers. At that point, I set the Visible property of the two intermediate measures to False and redeployed.
What I've learned is that calculations at the "row-level" are best performed through the DSV. You can then use those to build up more complex calculations within the cube.
(NOTE: One thing that needs to be added to the steps above is logic to handle division by zeros.)
Couldnt you have done a nonempty around the descendants on the cap rate measure?