Many applications allow you to import data. For example, when using Excel, you might query a database and put the results into a text file. Next, you might import the text file into an Excel document. The result of this action (importing data) is that you’ll have two copies of at least some of the data–the original copy in the database and the new copy in the Excel document. Once the data has been saved in Excel, it has lost its connection to the original source of the data.
An important question is: “What happens next month?”
The typical answer is “I will use the same process to import data for the new month into my Excel document.” Many people do this. However, the second, and subsequent monthly imports can involve a complex workflow. You probably want to keep the prior month’s data. You have to carefully append data each month in a way that preserves data you have previously imported in your Excel document.
An alternative approach, used by CHARTrunner Lean, is to leave your data where it lies. In this scenario, there is only a single copy of the data in the original data source. Chart definitions are set up to request the most recent data directly from the original data source. This data is not imported; rather it is requested (from the original data source) any time a user wants to see the chart.
This workflow prevents data duplication and ensures a relevant chart any time during the month. When a user wants to see the chart, the most current, fresh data, is fetched from the original data source–and the chart is rendered. No need to wait for the end of the month when the data analysts do their next monthly import and update cycle!