Creating virtual attributes with consolidations
This type of object is useful, fast, and it is calculated on the Intelligent Server side so it doesn't put load on the database. As the name suggests, it serves the purpose of consolidating row values. This means not only adding one row to another, but also doing row-to-row calculations.
Remember from previous chapters that there are multiple London or Paris elements in the City attribute, the schema was designed this way to respond to a specific requirement: allow the reports to display separate ZIP codes in large cities. Now we want to have a look at how much we sell in the entire city of London, but we don't have such an element in the City attribute.
So, we create our own virtual attribute to show, in one single row, a consolidated value for all the elements that represent the city of London and another row with the values for the rest of the UK.
Getting ready
You need to have completed the preceding chapters before going on.
