A modern RDBMS is quite a complex beast. Here is a ‘simplified’ block diagram of the components involved. Pretty darn good at abstracting the details from the end user. You dont really have to know how each ‘module’ fits into the entire scheme of things.. but it definitely helps.
For instance, you get to know that when you ‘edit’ a single ‘field’ in a ‘table’ in a ‘database’, the ‘entire page’ on which the data exists is written to disk – because a memory ‘page’ is the smallest unit of IO for a database engine.
In my professional career, I have studied a lot about databases and used almost about every product out there – dbase, foxbase, foxpro, Access, filemaker, Approach, MySQL, SQL Server, Oracle, Sybase, DB2…..
But I must admit nothing blew my mind like Microsoft’s SQL Server. It is a GIANT product with extremely intuitive and functional client tools. MS has always been about great user experience.. be it windows or office or visual studio or (sql server) enterprise manager. The ability to ‘trace and debug’ stored procedures.. priceless! They really have thought of EVERYTHING.