Single database architecture: A single database architecture supports a single database having many tables. It was by mainframes and minicomputers. Usually a single user takes administrative control over the entire database.
Advantage of single database architecture: Tables can reference to each other easily.
Disadvantage of single database architecture: When database grows larger, it becomes more complex.
Multi database architecture: There are multiple databases in a multi database architecture. Usually for each application there is a separate database.
Advantage of multi database architecture: Whenever a new application has to be added, then a new database is added for that application without interfering with any other databases Different users can take care of different databases.
Disadvantage of multi database architecture: Connecting one database to another and building relationships among them can be a difficult task.
Multi location architecture: In a multi location architecture, databases are aligned in a directory structure. Databases in the different directories can have different names. For each application there is a separate database. Minicomputer databases like Informix used this type of architecture.
Advantage of multi location architecture: A multi location architecture provides flexibility.
Disadvantage of multi location architecture: Just like multi database architecture, connecting one database to another and building relationships among them can be a difficult task.