I guess you're probably posting from the US, and this may be different from the UK. Most roles in the UK are handled by agencies and they will filter candidates, even if they don't know what a dba does.

It's been expressed as an opinion that the DBA is often not paid to match their skill set for a permanent role so this drives the more skilled DBA into becoming an independant ( contractor/consultant ). Having been part of the interview process for many years , normally to replace myself! it's an interesting topic.

Questions I ask are based upon what can be learned in the practical sense rather from a text book - this helps weed out those with good memories but no real practical skills/experience. Questions are largely based upon what skills the candicate claims in their cv.

There is an issue that questions must be the same to all candicates to avoid unfairness and being sued for discrimination - I've actually had candidates complain about being asked technical questions!

As I work with production systems, being a production DBA, I doubt the value of asking questions based upon CODD's rules - this is something which can be memorised and yet mean nothing - I'd be more keen for a developer to understand this , most don't.

Questions should not be subjective, so i avoid cursor questions as this is a subjective matter that's been argued to death in forums - in production support it's important to resolve problems quickly so I'd rather have a cursor solution in 2 mins rather than a convoluted non cursor solution that takes 6 hours to figure out!

My personal view of your requirements is that you're probably a bit out of touch, why would a SQL Server DBA really need perl? Sure a DBA should understand a SAN but the companies I work in have dedicated teams for infrastructure, storage, networking and so on. I can't think the last time I would have built a physical server - I'd install sql server but the actuall physcial server build is always another team- true I work blue chips - but the DBA can't be an expert in all areas outside sql server. ( I can build servers myself and have a pretty good knowledge of an o/s but I wouldn't expect a DBA to know much more than how to make sure memory was being configured correctly by the o/s e.g. switches )

The whole area of sql server is now vast and the chances of finding a candidate with high skill levels in all areas is pretty slim - it's important that the skills asked for are the skills for the job not just a chance to ask lots of impressive questions about skills and areas which probably won't be required for ther core areas of the role.