Why should you care about user data tables?
User data tables should not be in the system databases (master
, msdb
):
- In case of failure, there is a high chance that those tables will be lost.
- In the case of migration, these tables may be forgotten and not restored.
- It shows that some users may have excessive access rights to system databases.
- Also, maybe someone is running a query or pointing a third-party tool at the wrong database, deploying some objects, and not cleaning up afterwards.
How can you find user-created tables in the SQL Server system databases?
You can use the script below to list all user tables in master
and msdb
databases.
SELECT 'msdb' AS SysDatabaseName
,name AS UserTable FROM msdb.sys.tables WHERE is_ms_shipped = 0
AND name NOT LIKE '%DTA_%'
UNION
SELECT 'model' AS SysDatabaseName
,name AS UserTable FROM model.sys.tables WHERE is_ms_shipped = 0;
How to fix them?
- Rename the tables.
- If no problems after X (30?) days, delete them.
- It could also fix security, so this can’t happen again.
- Ideally, you want to add automated DDL (any object modifications) monitoring to log all.