Using Extract in MDX

Question

Hi Team,
I have a requirement to
Get all the Prescriptions of the Doctors (Including other Products) who prescribed My Product.
Scenario
1. Below is prescription details, One Doctor Prescribed 3 products
PRESCRIPTION_KEY   DOCTOR_CODE   PRODUCT_CODE   PRODUCT_DESCRIPTION
80548777                  111010503607   111140                LEVOPAN
80548740                  111010503607   112395                PROTERA-L
80548430                  111010503607   142495                PAN-L
34352343                  111010726343   142495                PAN-L
63442543                  345787748749   894845                TEMPO
My Query (Get the potential Market for my Product LEVOPAN)
Steps  to get the Data
1. Get the All the doctors who prescribed my product (e.g. LEVOPAN)
a. In this example it should be Doctor Code - 111010503607
2. Get all the Prescriptions by that doctor,
a. It should bring No. of Prescriptions = 3 (80548777, 80548740, 80548430)
Dimensions
Product (Product Description)
Doctors (Doctor Code)
Measures Group
No. of Prescriptions
Input to MDX(CurrentMember of Product)
My Product LEVOPAN
My Queries are:
----This is to extract the doctors and their total prescriptions who prescribed my product.
WITH
SET [GHI] AS
EXTRACT((NONEMPTY(([DOCTORS].[Doctor CODE].[Doctor CODE].MEMBERS,[PRODUCT].[Product Description].&[PAN-L]),
[Measures].[Prescriptions])),[DOCTORS].[Doctor CODE])
MEMBER [MEASURES].[A] AS SUM([GHI],[Measures].[Prescriptions])
SELECT
{[Measures].[Prescriptions]} ON COLUMNS,
{[GHI]} ON ROWS
FROM
[MyCube]
----This is to extract Doctors who prescribed my product
SELECT
{[Measures].[Prescriptions] } ON COLUMNS,
{NONEMPTY([PRODUCT].[Product Description].&[PAN-L]*{[DOCTORS].[Doctor CODE].[Doctor CODE].MEMBERS})} ON ROWS
FROM
[MyCube]
Please help me on this scenario.

Answer 1

I want to have this in a Calculated member in a cube which will give me result like this
Product | Prescriptions
Pan-L | 5824
To get the expect results, you can create a product dimension and product attributes. In the Aggregation design time, include this attribute.
How can aggregation design help in this scenario,..please explain me as my understanding on Aggregations was that they will create aggregations and save in database to make retreiving faster.