Incremental loads
Another important advantage of designing an appropriate data architecture, is the fact that it eases the construction and maintenance of incremental load scenarios, which are often required when dealing with large data volumes.
An incremental load is used to transfer data from one database to another efficiently and avoid the unnecessary use of resources. For instance, suppose we update our Base QVD Layer on a Monday morning, pulling all transactions from the source system and storing the table into a QVD file. The next morning, we need to update our Base QVD layer so that the final QlikView document contains the most recent data, including transactions generated in the source system during the previous day (after our last reload). In that case, we have two options:
Extract the source table in its entirety.
Extract only the new and/or modified transactions from the source table and append those records to the ones we previously saved in our Base QVDs.
The second option is what...
