Disk Space Side Effects of SQL Server Data Tools

SQL Server Data Tools (SSDT) installs LocalDB, a new version of SQL Express. For details on LocalDB, please refer to Introducing LocalDB, an improved SQL Express.

As Kevin Cunnane explains in the SQL Server forum thread Importing database always defaults to localdb, creating a SQL Server database project by SSDT always creates a database on LocalDB, (localdb)\Projects since September 2012 update of SSDT. And of course, one cannot change this behavior – well, why should we, just because we do have a SQL Server installed on our dev box?

Kevin points out that the database is empty and only populated on debug/deploy. So another 4 MB are wasted on my profile drive. Why on my profile drive? Because the database files are located on %user%/AppData/Local/Microsoft/VisualStudio/SSDT. Of course, you can delete the database, also from within SQL Server Management Studio, as soon as you close the database project. But when you re-open the project, the database is re-created.

The system databases, error logs and event files are located at %user%/AppData/Local/Microsoft/Microsoft SQL Server Local DB/Instances/Projects (or V11.0, if you do not have September 2012 update or later installed). Here you can remove the event log and system health files from time to time, if LocalDB won’t do so. If you like to test it (I didn’t): the directory is set in the registry under HKEY_CURRENT_USER\Software\Microsoft\Microsoft SQL Server\UserInstances. In case there is more than one entry below this key, have fun 😉 This seems to happen when you have SSDT installed before the September 2012 update, and then updated it.

Trying to change some settings of LocalDB using SQL Server Management Studio, like database default locations or error log recycling, led to an ‘Access denied’ exception on my machine.

But that’s not all. There is also a .dbmdl file created, having about 8 MB on my really small sample database project. This file can be deleted too, but will be re-created. Some guys on the web say that .dbmdl files are only used as a cache per user. This is why they should not be put under source control.

So in case you run out of disk space, check your profile for LocalDB database, log or health files and your projects for .dbmdl files.

Where Do SSDT SQL Scripts Connect To?

In some software projects I used empty Visual Studio solutions to create some kind of database projects. I added SQL script files to the solutions to create all database objects, like tables, functions, stored procedures, views, constraints, and so forth. A batch file was used to run all these scripts against the database.

One common part of these script files was a snippet of sample code to test the database object, e.g. a stored procedure or function, directly from inside Visual Studio. This snippet both documented the use and gave a quick way to test changes. Of course, this snippet was intended to be used only when connected to a local SQL instance to avoid damage in any other environment!

Playing around with SQL Server Data Tools (SSDT) in VS 2012, I was looking for the ability to connect a function script to my existing local database. Under the menu item SQL / Transact SQL Edit / Connection there is the ability to connect to a database. To my surprise, I was not asked to which SQL instance or database I would like to connect to. At least, clicking the connect menu item seemed to do nothing at all.

But running the script worked, and the result window told me that the function was created successfully. I was wondering where. Searching for a database selection option in the toolbars, as I know it from the SQL script files in VS 2010, failed. There is no such possibility. Was the function created in the master database? But which SQL Server instance was used?

Well, Visual Studio showed me the answer to these questions all the time, but I did not noticed it.

When you edit a function or a stored procedure script file of a SQL Server Database project – not a simple SQL Query file! – you will find these information in the properties window on the right (or wherever you have placed it). The properties window shows the connection name, logon name and so forth, and whether the connection is open or closed. You cannot change any entry. These properties are not available for table script files of the project, which can’t be connected to any database at all from within Visual Studio.

But the properties window does not tell you the name of the database. Almost, it is the project’s name. But it doesn’t have to. The name can be found in the .sqlproj.user file, located in the project directory. Of course, you can edit this file to change the name.