Performance Tuning with SQL Server Dynamic Management Views

DMO Security and Permissions
Chapter 1: Using Dynamic Management Objects
As noted in the previous section, from SQL Server 2005 onwards, the master database is
no longer the main system database for storing all metadata and operational system data.
All system metadata (except that relating to backups and SQL Agent) which was, and still
is, hosted in the msdb database, is now sourced from the resource database. Incidentally,
the fact that metadata on SQL Server Agent jobs and backups is still stored in msdb
explains why you won't find DMOs related to these areas.
The resource database is completely shielded from even those who are granted the
system administrator role rights. It exists as two files, mssqlsystemresource.mdf and
mssqlsystemresource.ldf, stored in the default data folder of any SQL Server 2005+
instance. The resource database can't be queried, nor can it be backed up by anything
other than a file copy. It is completely shielded from use.
In the process, the master database has been transformed into a sort of abstraction
layer, housing the compatibility views, catalog views, and DMOs that ultimately expose
this metadata to the end-user, in a controlled and secure way. In order to view the data
in these views and DMOs, unless you are the system administrator of the server, you will
need to be granted one of two privileges, depending on the scope of the object you are
querying:
• server scoped objects require the VIEW SERVER STATE privilege to be granted to the
relevant login; most DMOs covered in this book required this privilege
• database scoped objects require the VIEW DATABASE STATE to be granted to the
relevant login.
Note that these privileges allow a DBA to view the state of the server without having
system administrator rights. Using these permissions for all users who only need to access
the DMOs, rather than giving them system administrator privileges, could save you from
the "Oops, I dropped a database by accident" phone call late one evening.
21