The SQL Source Control uses the default trace in SQL Server, however this is stored in the tempdb which can be cleared after a restart.

RedGate suggest using a change log database as shown in the link here: https://documentation.red-gate.com/display/SOC3/Logging+changes+to+shared+databases

However, this requires you to manually edit the Engine Options xml file in the user profile, this should be configurable in the UI making setup a lot easier. If you have 10 or more developers it requires that those developers maintain their own Engine Options xml file.

It would be great if this is configurable through the UI on Setup when Linking the database to a source control repository therefore requiring the user to be asked whether to use a ChangeLog database or stick with the normal process.