Only SQL as a Language Which is ancient ugly for algorithmic programming and slow. It is also forces you to use a lot of foreign constructs to “original” MySQL style - to process data via cursors, handle error via Handlers etc. If you spent last 10 years writing Stored Procedures for Oracle or DB2 it may be cool and convenient for you, but not for me .

Lack of Debugging I like to be able to debug software, if not full blown debugger I’d like to have things like echo and var_dump. Due to the context of execution these are not easy though. Of course you can code a little helper Debug Storage Procedure which will log some information in MySQL table but it is not convenient enough.

Bad Parser Error Messages MySQL Parser is in general far from perfect when it comes to error handling. “You have an error in your SQL syntax … near ” at line 1″ is not very helpful even when dealing with large queries but for Stored Procedures that is the real issue. So you have to overcome few road blocks even before you start fighting with debugging. 

Read more