Oracle IS the gorilla, but with their recent pricing/licensing moves, more large orgs are exploring moving to SQL Server, especially ones that are already a Microsoft shop. My company is doing just that.
Why not explore PostgreSQL? You would be free of licensing/pricing moves.
Re:Announcing SQL Server on Linux
by breakingcups on Tuesday March 08, 2016 @10:54AM
(#11245980)
Not GP, but I've found SQL Server significantly easier to both install and manage. Performance-wise I've yet to encounter a significant difference.
I suppose Microsoft is pretty popular in beetween those 2 markets.