> I have successfully designed systems which could be easily migrated between different RDMS' with minimal changes. Not that I doubt you, because I know with t

> I have successfully designed systems which could be easily migrated between different RDMS' with minimal changes. Not that I doubt you, because I know with the right trade offs it's possible, but is the operative word "could" or did you actually ever migrate one of those architectures? > Obviously to go to no-sql or other less conventional storage is a different story. Ruling those out feels a bit disengenuous. There are plenty of good reasons to need to migrate to or from a relational DB.