# Special database access

You can also access databases from the classpath/modulepath or from a jar file (in the classpath/modulepath or not) as read-only databases.

You can create in-memory databases for use in testing and development and for processing temporary or reproducible data. See Using in-memory databases for details.

- Accessing databases from the classpath/modulepath
  In most cases, you access databases from the file system. However, it is also possible to access databases from the classpath/modulepath. The databases can be archived into a jar or zip file or left as is.
- Accessing databases from a jar or zip file
  It is possible to access databases from a jar file. The jar file does not have to be on the classpath/modulepath.

Parent topic: Connecting to databases
Related concepts
Connecting to databases within the system
Connecting to databases outside the system directory
Conventions for specifying the database path name
Related reference
Database connection examples