Circular Reference

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Circular Reference

While building a data model, it can be very easy to create circular references as you add in all your tables. As QlikView cannot handle these in its selection engine, they must be avoided. However, should your data model have them, QlikView “loosely couples” some of the offending tables. This means that the loosely coupled tables will not be restricted in any selection. Sometimes you will get the following message.




This indicates that QlikView has detected a circular reference and has loosely coupled some tables in the data model. 

If you view your table structure (Ctrl+T), you will notice that there are some dashed lines connecting at least one table; this is where the circular reference has been detected and needs your attention. 







In many cases, including the preceding one, circular references are caused by commonly named fields being linked together (with synthetic keys or without) when they shouldn’t be. Removing the synthetic keys or stopping the commonly named fields from linking by using aliases may solve the issue. 

However, if you are still left with circular references after removing any erroneous links, you will need to look closely at the rest of your data model to find where you need to alias fields to break the circle. 

If you leave them in place, any table affected by the loop will be loosely coupled, which will dramatically affect the document’s ability to perform as you would like. In fact, it may not perform at all, as big portions of data may not be selected as expected.


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