Hi All, I wanted to understand performance wise when join would be more preferable. Either allowing qlikview to join using associative join capability or making the QVDs join physically. Thanks for your help in advance.
Hi Jose Thanks a lot for responding. the first link is taking me to an excel sheet and the second link helped me how to datamodel but did not answer my question that is , Is it good to allow qlikview to make joins or else the developer should do physical joins.
My answer would be it depends. It depends on the workflow of your company:
If you have a dedicated team that focus on maintaining databases, datamarts, etc, then it would be a good choice to tell them to either create special/custom views (QlikView is able to connect to normal tables and also to views) that contain the information you need for analysing your data in QlikView, so you leave most of the duties of ETL to the people in charge of DB/DW.
If you don't have a dedicated team or you don't have a DW or your data is not centralized in a single data source, then somebody has to do the transformations and integrations of data. Then you'll have to construct an ETL-like structure within QlikView. You can achive that creating different levels of data using QVWs and QVDs.
However, technically speaking, SQL is a much more developed language for doing joins, unions and any other transformation of data. So in conclusion if you can do most of the ETL with SQL, then do it, but as QlikView is a suite that contains its own script engine, you can also do joins, concatenations, mappings, etc, but the point is to achieve a good balance (and teamwork) between the duties done by a DBA and the features offered by QlikView,
