4 ms·

is it not standard practice to support at least two different db systems !?

• toyg 10y ago
  For certain values of "support". Say you start on Oracle and then want to move to SqlServer? Migration will likely be a risky endeavor, even if the application supports either db when starting from scratch. To begin with, you'll need something to copy schemas across, be it in the app itself or not, and hope everything made it across. Then you'll have to hope the app doesn't need db-specific stuff (say, a sequence that you only get on sqlserver) that you don't have because you started on Ora. And then you'll have to move all the 3rd party tooling and hacks that you built over the years around that same database - from backup solutions to custom queries etc. It's rarely as easy as "copy it all and turn it back on", and all this work often has to be done by expensive application specialists. At that point, having to choose between paying hundreds of thousands to move db, or a few extra thousands per year to keep things as they are, the business decision is not as simple as one would think.