Re: Sybase/SQL
They were the same thing in what, 1991 or so? Today if you know one you'll fell at home on the other quite quickly but they've both been re-written several times since 1991!
They're both good RDBMSs and each have features the other doesn't but each new version both closes and opens the gap. Sybase is now called SAP ASE of course.
I work with both a lot and personally I slightly prefer ASE but I prefer either over Oracle any day of the week.