A well designed data model is a significant factor behind the success of a QlikView project. The architecture and structure of a data model must be well thought through to avoid strings of complicated and unnecessary data presenting itself in the future.
Let’s focus on what QlikView professional Steven Dark says about rocky data model foundations and starting a QlikView project the right way:
What all too often happens is that the data model from the underlying source database is pulled in, with its existing join fields and system field names. A developer will be forced to deal with some immediate issues, such as synthetic keys, but will sometimes (once they have something that ‘kind of works’) leave it at that. This can sometimes be okay on small data volumes – but it certainly will not scale and causes much extra effort down the line.
When building a data model using QlikView:
- Segregate your data into distinct columns
- Avoid ‘data islands’, which are documents that do not connect to other data or to the -model in any way
- Don’t pull redundant fields into your data model as this causes performance issues
- Do not create more than one field with the same synthetic key
- Concatenate fact tables together rather than trying to join them
- Simplify and rationalise the data model in the load script
- Watch out for issues with non-numeric join keys that can be caused by rogue spaces or mismatch of capitalisation