SQL is a query language and an RDBMS is an implementation. It's like calculus, you can compute efficiently or inefficiently it has nothing to do with calculus.

SQL is a query language and an RDBMS is an implementation. It's like calculus, you can compute efficiently or inefficiently it has nothing to do with calculus. The same developers that make retarded SQL queries make god awfully slow programs with their pointer chasing mess because they don't understand that their programs run on actual real hardware and that a cache miss is pretty much the single most expensive operation a modern CPU can make by 2 to 3 orders of magnitude. They just go on and on about interfaces, inline methods, virtual methods, etc, and never check whether their fancy smancy object fits on a cache line. Its the same with databases they just talk about 'webscale' and 'big data' abandon SQL and then wonder why their DB explodes once it reaches 100 GB.