Articles relating to issues I've encountered whilst working with Microsoft SQL Server:
If you have a database stuck in SINGLE_USER mode, where it is not possible to set it to MULTI_USER because another process has excluding use to it, there are a couple of methods to try which will regain access to it.
I recently came across an issue where a database had a corruption and when trying to fix it using DBCC CHECKDB, it came back with the following error: Check terminated. A failure was detected while collecting facts. Possibly tempdb out of space or a system table is inconsistent. Check previous errors.
I come into the office recently to find one of our VMware hosts was throwing a wobbly and had left several virtual machines in an unresponsive state. The option for guest OS shutdown was unavailable, so they needed to be force stopped and the host needed rebooting to get everything up and running again. After powering up the VMs, one of the SQL Server databases had been left in suspect mode.
If a table has been copied from one database to another, or the ID autoincrement column needs to be switched off for identity row insert, you can reseed the ID column to increment from a defined value.