Vendor lock-in and relational databases

Avoiding features to enable portability

In the early 2000s the company that I was working for got a fright when the database vendor that we were tied to came out with a different approach to charging for their software license. Having applications on "the Internet" got the vendor's attention so they wanted to have a way of deriving more revenue from websites.

From then on all developers on our relatively small team were directed towards avoiding using any non-standard features of that particular database engine, as it would make it more difficult for us to be able to transition across to an alternative vendor. For example, stored procedures were only allowed for edge cases such as an advertising engine (yeah, we rolled our own advert engine for a customer back in the day).

Keep in mind that this was back when self-hosted physical servers were pretty much the only way to operate, well before cloud computing such as AWS even existed, so it was a big deal to set up a database server, involving direct license agreements with vendors.

Much much later on my career, we had guidance come down from senior management that there was frustration that the cloud vendor knew about the broad range of their services that we were using, so felt confident that we were not a flight risk of giong to another provider. On that basis we were instructed to either not make use of vendor-specific services, or wrap them in such a way that our services would be able to be ported across to another cloud provider. That tied up quite a bit of developer time, and left us restricting our implementations to the lowest common denominator level of functionality when it came to considerations like messaging systems.

"Standard" functionality doesn't mean it's the same

Looking back after a couple of decades, my recent dabbling with transaction isolation levels has been a real eye opener as to how much relational database engines can differ in the way that they go about complying to standards, even without going into obvious vendor extensions.

This has reinforced an opinion that some former colleagues of mine expressed while we were working together on a large cloud transformation project during my time in London, "You'll never end up changing database, so just use whatever it offers." 

Don't get me wrong, vendor lock-in is still a risk to keep in mind, but it needs to be weighed up against the opportunity cost of not making use of the differentiating features that could make the product worth paying extra for in the first place.