I have some questions about data modelling as per below,
When we can link the table we can create relationshup in between tables so that data from both table is associated what happen if we can not link the table.
when we are renaming the fields for joining two tables is it possible to loose some of data in perticular column.
If so what are diff ways to avoid this.
Moreover also suggest me good some links for data modelling preperation
As Manish says renaming fields will not lose you any data. Associations in QlikView work very flexibly and generally how you would wish them to.
If there is no link you will get a Data Island, these are generally a bad thing - unless you are doing it for a specific reason. The biggest risk with data islands is if you include fields from more than one data island in a single chart object you will get a Cartesian product and vastly more rows than you are expecting - sometimes even crashing QlikView.
I have written a couple of blog posts on data modelling in QlikView that may be of interest to you:
if you are not created a link between two tables called association, then two tables dont know about each other and will remain separate in data model, itz called data island.
By renaming the field, you are not going to lose any data inside the field, you are just renaming the field name
Deepak, you're right about data islands. Although you need to see if you could alternatively have used join or applymap instead to keep the data model simple. There are exceptional cases where you want static list boxes, classic example is when you want to have a chart with dynamic expressions and dynamic dimensions. In this case you will have 2 tables (data islands), one for the list of expressions and the other for dimensions.
