Alternative to Count Distinct

Count distinct "Count( Distinct <Field Name>)" is an expensive expresssion in Qlikview. Whenever used, it turns Qlikview to use single core instead of multi-cores resulting in slow performance of the app.
By making a small change in data model we can replace COUNT DISSTINCT with SUM function and improve the app performance marginally and increase app response time to users actions.
To achive this add another field in Qlikview table having value 1 along with the field you need to count.

Example:

Bookings:
LOAD
    [Member Id],
    [Booked Date],
    [Transaction Id],
    [Booking Amount]
FROM Bookings.qvd (qvd);

"Member Count":
LOAD
    [Member Id],
    1 AS "Unique Members"
Resident Bookings;

To count distinct members
COUNT(DISTINCT [Member Id]) can be replaced with SUM([Unique Members]).