Subset ratio needs to be 100%

[Anonymous]

hi all,

Is subset ratio needs to be 100%? If yes can anybody explain me why?

[Kushal_Chawda]

see this

information density and subset ratio? What is the use of this?

In above thread you will get the knowledge about subset ratio. Now it is good to have subset ratio as 100% because you will have all the possible Key values between the connected tables.

[Anonymous]

thanks for the reply but if the i want to find which records are not associated with another table. so in that case the subset ration will not 100% so is fine?

[Kushal_Chawda]

That depends on the scenario.

let's say you have Fact table with below details

ID Sales

1 100

2 200

3 300

and dimension table with below details

ID, Country

1 US

2 UK

Now when you create the report with sales by country in Qlikview you will get report like below

US 100

UK 200

-     300

So in this case, it is not fine that the subset ratio is not 100%, because country name cannot be blank if sales is associated with it

[Anonymous]

ok thank you so much

[Kushal_Chawda]

Please mark the answer as correct or helpful

[arvind_patil]

Hi Saloni,

IT may help you:

Subset ratio, which shows the percentage of all distinct values for a field in the

table compared to all the distinct values for that field in the entire data model. It is

only relevant for key fields since they are present in multiple tables and do not all

share the same value.

Subset ratios can be used to easily spot problems in key field

associations.

     For example, when the combined total of subset ratios for multiple

tables is 100 percent, this may indicate that there are no matching keys between

these tables.

REF: QlikView 11 For Developers..

Let me give you simple example

Sales:

Load * Inline

[

  Customer, Sales

  A, 100

  B, 200

  D, 300

];

Customer:

Load * Inline

[

  Customer

  A

  B

  C

  D

];

If you write above sample script and will check the Table (CTRL + T), you will find two tables.

Sales and Customers

On Sales Table, if you hover the mouse on Customer field, you can see the Subset Ratio is 75% because there is not sales data for Customer C.

Now if you change the script for table Customer like below..

Customer:

Load * Inline

[

  Customer

  A

  B

  C

  D

]

Where Exists (Customer);

If will not load the Customer C as there are no sales data for the same.

Now check the Subset Ratio. It will be 100%.

If subset ratio is less than 100%, the key is called as Primary Key

but for 100% it is called as Perfect Key.

Thanks,

Arvind Patil

[Kushal_Chawda]

was my answer not helpful? salonipande27