For long term maintainability, absolutely abstraction is the way to go. Any pros and cons listed now can help you decide, but what about a year from now? Two? F

For long term maintainability, absolutely abstraction is the way to go. Any pros and cons listed now can help you decide, but what about a year from now? Two? Five? This goes double if you are considering commercial products. For various reasons we are forced to use $Vendor, but we are not a commercial shop and we always have the fear factor that $Vendor will price us out (they occasionally try it on by "forgetting" our academic discount). We hid all the DB interactions in two layers (one to hide the relational nature of the database, and the other to hide the specific implementation). As a result, I am in the position to tell $Vendor "How much? Well, you can give us this price or we can move to postgress - either is fine by me". And mean it. And they can tell.