Concatenation

Another way to optimize your data model in QlikView is through concatenation.

Concatenation is a way to combine or merge tables. It is similar to Union All in SQL. It appends rows from one table to another. The result of concatenation between two tables (Table1 and Table2, for example) is that a new table contains the sum of the numbers of records in Table1 and Table2. Concatenate is used when you have two fact tables in your data model. Two fact tables are not good for your data model. You can combine them using concatenate or link tables. Link tables are explained in the next chapter.

Concatenate is also useful when you have to combine two tables with similar structures. Say, for example, your organization has an Employee table that stores employee data. Your organization buys another company and now wants to merge the details of the employees of this new company with the existing Employee table.

Let's explore different concatenation options:

• Automatic concatenation: If...