Your Active File Directory is where local files from the repository are stored when you perform a Get Diagram operation from the Repository. There are two types of Get Diagram operations:
● Repository Merge: If there is a local copy of a Diagram (dm1) in the Active File Directory then the Repository will proceed to merge the Repository dm1 with the local dm1. If there are any conflicts resulting from changes between the local dm1 and repository dm1, you will see the Review Changes Dialog which allows you to resolve the conflicts. If the local copy of the dm1 is checked in (Blue Locks on all objects), then the local copy will be opened and a Get Latest Diagram operation will be performed.
● Clean Get: If there is no local copy in the Active File Directory, then the Repository will create a new copy of the dm1. There will be no conflicts to resolve. Typically this is a faster operation than if the repository needs to merge changes between the repository dm1 and local dm1 during the get process.
You can get an entire diagram or just a submodel (partial dm1 get). For normal work on a dm1 file you should get the entire dm1. The local file name will be the same regardless of whether you retrieve a partial dm1 or the entire dm1. This makes it difficult to switch between submodels if you are retrieving partial dm1s from the Repository. If you intend to make a change to only one submodel and only that submodel, then you should get a partial dm1, but for all other use cases, you should get the entire dm1. It will be much easier to switch between submodels and the logical/physical models when the entire dm1 is retrieved. Also, the Where Used tab is not available when you retrieve only a partial dm1.
The Active File Directory should be local to your machine and not located on a network shared with other users. As you are working in the Repository you can save changes locally to the dm1 in the Active File Directory through the normal File > Save operation. Working off-line is a great way to maximize productivity. As long as you check out everything you need to work on before going off-line, you can safely save changes locally until you decide to check them back into the Repository (see Checking In/Out Objects below for more detail).
Performance Tip! If you want to get working right away with a model, you can open it directly from the active directory. The object checkout status from when you saved and closed the file will be preserved and you can start working immediately.
If you are working with multiple Repositories, you should use different active file directories for each Repository so that there are not any file name/sharing violations for similarly named dm1 files. A good practice is to create one Active Directory with subdirectories for each Repository that can be easily identified. This is usually reserved for Admin users, not normal daily work within the Repository.
Note: Usually a second repository is for a test environment when testing upgrades of ER/Studio. Multiple repositories are not advisable solely for segregating models.