I'd like to give users the possibility to create sample Data after installing a package, but I want them to do this only if they want, so I don't provide the data creation directly in the postInstallScript. In fact I have a custom VF tab with a button that , if pressed, creates the sample data. The solution that I'm reaching for would be to have a situation where IF the package is installed for the first time (context.previousVersion() == null) the user has the possibility to create the sample data (creation handled by a class, this is not a problem), but if it's an upgrade, or if the user has already created the sample data, the action is avoided. So I need a static variable to store the information about wether or not data was created (IsSampleDataAlreadyCreated, something like this). How can this requirerment be accomplished? Is custom setting the solution?