DP Code - PP and PPV DB fields

The projects table in the database contains three fields related to Post-Processing and Post-Processing verification.

• checkedoutby -- can be either PP or PPV. It is also where the username is stored for assigned PPers when a project is going through the rounds. If a posted project never goes through PPV, the final value is the PPer; if it does, the final value is the PPVer, so after a project is posted, it's largely irrelevant.
• postproofer -- stays empty until either
  • the PPer uploads for PPV or
  • the project gets uploaded to PG
• ppverifier -- defaults to NULL and stays that way unless a project goes through PPV and is posted to PG by the PPVer

When a Post-Processor who does not have DU uploads a project to the PPV pool, the PPer's name is copied from checkedoutby into postproofer (that is, the PPer's username is in both places).

When a PPVer checks the project out for PPV, checkedoutby changes to the PPVer's username.

If a PPVer returns the project to the PPer, the PPer goes back to being checkedoutby, and their username is removed from postproofer.

The ppverifier field is not filled in until a project is posted.