If your data is coming from some connected data sources, extracting such data from a workbook will let you work on that data even if you are disconnected. The extracts are also useful when dealing with large data files as you can apply filters to select only a few rows (based on conditions).
Let's use the sample file Sample – Coffee Chain (Access)
. Open a new worksheet and select Sample – Coffee Chain (Access) as the data source.
Once the data is loaded on the worksheet, perform the following steps to extract the data:
Robin Kennedy from the The Information Lab Team, a Tableau consulting firm, has written a great insightful blog article about the reasons for a Tableau data extract. You can find this blog post at http://www.theinformationlab.co.uk/2011/01/20/tableau-extracts-what-why-how-etc/.