I am new to tableau.I want to create a dashboard with the following requirement. In the source table, there are three different status('OK','SU','TX') for a particular product in a particular day. The status column overwrites with the new status when the status gets change. I want to create a report that shows the product Id, previous day status(if the previous day status='TX'or 'SU') and today status. Should I maintain a separate table for the above requirement or is there any other method in tableau?
If the data is overwritten then it's gone. Therefore, if you want to know the status of the previous day, you'll need to keep the previous day data somewhere.
Tableau isn't a database, it's a visualisation layer, so the data should be stored elsewhere and fed into Tableau to create your dashboard.