I was involved with SQL Server in a pretty general type of way for many years working at first in support, then development. Once I had made up my mind what I wanted to specialise in it made a huge difference to my career.

I managed to talk my then manager into having me start out as a Junior DBA and worked on my own at nightschool to get a BSC in computing science and an MCITP in SQL 2008.

Although now there are different types of DBA, you have production \ development \ BI \ Warehouse DBA's so it can be even more specialised again.

These days I am more of a production \ development DBA but also supporting our Warehouse and BI systems so getting back to being a bit more general in DBA terms but with a strong understanding of the perfromance, HA and DR side of things.

If you want to specialise you have to be willing to put in alot of personal time studying and trying out solutions. But the rewards are being happier in your job, being more confident in what you do and in most cases better paid.