Scary SQL Server stuff: tombstones, phantoms, blobs, ghosts and zombies
This post mixes the spirit of Halloween and the passion for SQL Server :-)
Have you noticed how SQL Server has a number of things that seem right out of a horror movie?
As a test of your SQL Server expertise and for a fun Halloween trivia game, try to describe the items in the list below in the context of SQL Server.
If you can’t, follow the links to figure them out:
- Tombstones. Marking the burial places of your deceased data. If you don't keep them, you might end up meeting the undead. https://msdn.microsoft.com/en-us/library/ms186771.aspx
- Phantoms. Seeing things that are not there? These haunted queries can only be avoided with proper isolation. https://msdn.microsoft.com/en-us/library/aa259216.aspx
- Deadlocks. Weird things happens when hairy transactions collide. If one of those wraps around you, you might end up as the victim. https://msdn.microsoft.com/en-us/library/ms178104.aspx
- Blobs. Oh, the nightmares from these huge things sucking the air out of your database. Your only way out may be pushing them down a stream. https://msdn.microsoft.com/en-us/library/3517w44b.aspx
- Kill. Why would a database need such a command? Well, make sure you're well behaved it might never be needed. https://msdn.microsoft.com/en-us/library/ms173730.aspx
- Crypt properties. Tales from a database that implemented additional security. Just make sure you don't misplace your keys. https://msdn.microsoft.com/en-us/library/ms189536.aspx
- Hash Match. It's not a competition to see who's the fastest slasher. https://msdn.microsoft.com/en-us/library/aa237090.aspx
- Drop user. Users don't really live forever, after all. https://msdn.microsoft.com/en-us/library/ms189438.aspx
- Ghost rows. An army of ghosts, all perfectly lined up? Not really. https://msdn.microsoft.com/en-us/library/ms188436.aspx
- Zombie rowsets. What's Halloween without zombies, even if they only show up in small places. https://msdn.microsoft.com/en-us/library/aa258325.aspx
- Execute reader. Sounds like a curse on whoever reads your data. But it's actually quite useful and fast. https://msdn.microsoft.com/en-us/library/9kcbe65k.aspx
- Shadow Copies. Not as scary as it sounds. It's much scarier when your data goes bad and you don't have them. https://msdn.microsoft.com/en-us/library/cc966520.aspx
- Nested Triggers. It could be a code for snipers waiting to hit you from the rooftops. But it's much harder to explain than that. https://msdn.microsoft.com/en-us/library/ms190739.aspx
- RIP. No, it's not an epitaph. It's a way to help you clear your tracks and achieve compliance. https://msdn.microsoft.com/en-us/library/bb326650.aspx
And, of course, there’s a number of Wizards all over the place.
If you know any other good ones, please do share in the post comments.
P.S.: I was also reminded by Kalen Delaney of the classic "Halloween Problem" which can cause pretty scary results, as described at https://en.wikipedia.org/wiki/Halloween_Problem. Not specific to SQL Server, but there was a related issue with SQL Server 7 : https://support.microsoft.com/kb/248441.
Happy Halloween!
