Should I delete or disable a row in a relational database?

Question

In a brand new program where space isn\'t really that big a deal, is it better to delete a row or to disable a row by let\'s say a boolean \"Disabled\" and have the program

Answer 1

This should be determined by the application needs. I have done it both ways. I have some applications that need to support undo as the cost of removing a row -- and the cascading deletes that are caused by that -- are too expensive to not have it. Normally, though, the applications I have done require the user to confirm deletes, then just do as the user has asked. In some cases, you must delete the data due to privacy concerns. That is, if the user requests to be removed, you need to really remove it, not just mark it as not current. In other cases (like tax-related transactions), there may be reasons to keep data in a non-current state until no longer required by law. I have applications that fit in both categories.

Various strategies can be used in the case where you need to keep "archival" data. Depending on whether it needs to be immediately available you can push it to archive tables that are either kept or backed up and cleaned out regularly. If there is a need for undo you may want to keep it in the current table and just mark it by setting a flag. It really depends on the complexity of your schema, the requirements of the application, and personal preference to some extent.