What is wrong with stored procedures ? They are not fashionable nor especially expressive, but they perform reliably and they do pretty much what anything that might be expected from relational logic.
But maybe that's my enterprisey bias.
But maybe that's my enterprisey bias.
Testability, tooling and the open-source ecosystem and either bad or non-existent. Writing PL/SQL is the worst environment I've worked in. That database sent emails, processed CSVs scheduled jobs, etc. yet there was still a web app to maintain next to it.
They're OK for certain things like essential triggers or performance-sensitive functions, but I would never deliberately put app logic in there. Major red flag.
- often unique to that DB, so locks you in
- Scaling that code is now tied to scaling your DB tier
- Tooling is often very inadequate
- Versioning and backwards compatibility of code can be a challengeNot because of slow queries, but just the cost of executing the stored procs themselves.
If you're properly testing the code in your application that exercises persistence, that means your test harness runs a real database like the one you're running in production and thus you can also write the database logic tests using your own application's testing facilities.
Of the things you listed, "the database sends e-mail" is the only one where I'd think you'd have to change the code at all, and have the database go through a mockable middle-man so that it becomes testable; but everything else can be comfortably tested from a test suite that is able to talk to a real database.
That's really a bad, very bad use of SP. They should only deal with and care about the data, not doing any interaction with any external systems.
I expect at some point we'll have a similar initiative around cloud providers.
This is pretty good since one can generally fast unit test DB code with an embedded database.
The Oracle version had a lot of logic written as SP. I migrated them to MySQL SP.
So the conclusion is: SP don't make it impossible to migrate from one database to another, and second: yes database migrations do happen.
Also: all database migrations I have known involve Oracle in one way to another. Oracle salespeople are way too nosy.