Questions regarding .mdf database filetype

Question

Are the following statements about Microsoft .mdf files correct?

• Microsoft's .mdf file-type can be used by both the LocalDB and the full Server database engines.

• The .mdf file does not care which of these two options are accessing it - so you could use either to access any given .mdf file, provided you had permissions and password etc.

• The LocalDB and the SQL Server are two options that can be interchangeably chosen to access .mdf files depending on the application requirements.

Answer 1

.mdf is one of the two formats used by SQL Server:

• .mdf stores the actual data,

• .ldf stores the transaction log.

The .mdf file can indeed be used both by SQL Server and LocalDB (but not at the same time), but you should be aware of LocalDB limitations, such as 10 GB database size support.