How to tune the qlikview application?

[#1]

Hi Team,

I am new to qlikview, Can anyone suggests me how to tune the qlikview application in all ways?

Ex: I have a qvd, that qvd size huge(1gb).

While i creating qvd i have written SQL code  like this

Select * from High

High is view

Inside high View:

Select a,b,c,d,e,f from minimum

union

select a,b,c,d,e,f from maximum 

when i ran this high query in sql it's taking time as 40 mints, I want to tune this one. Can anyone help me to tune in different ways.

Thanks.

Priya