As you might noticed from my original conference schedule, I've been really interested in learning a lot of completely new stuff. Good news - I've got a lot of things to review, bad news - some answers were not what I was expecting and now I am struggling to fit them in the picture of a sane universe.
Let me start from MySQL. A lot of thanks to George Trujillo and Dave Stokes for providing tons of really deep insights on the role of this database in the contemporary IT environment. It was a big surprise for me to realize how much influence MySQL got in the corporate world - for example, as far as I understood, if you use Expedia.com, the search is done via MySQL while ordering is done via Oracle.
It seems that this dual implementation slowly but steadily becomes "a new norm" - there is one major database, implemented using high-end solution + there are other side projects done via MySQL. Reasons are usually split into two groups:
- money: even big corporations think a lot about costs of Oracle licences. As a result I've heard from a number of people the following corporate policy: "We do it in MySQL, unless you can prove that it cannot be done there"
- read optimization: let's keep the picture clear - the main purpose of MySQL from the very beginning was to quickly bring the data up. Everything else is "nice to have", the MySQL development team stays very focused on that vision (I've talked with them!)
- flexibility: another big surprise for me was that MySQL is really a container of different possible storage engines. And there are dozens of them - each tunes in its own way. Yes, InnoDB is the closest to "real" RDBMS with ACID compliance, memory processes etc - but in a lot of cases you just don't care about all that overhead! Of course, you pay the price for it - from the questions of the audience I understood that a significant percentage of performance issues is usually related with the selection of a wrong storage engine. Sorry, that's what a reverse side of "flexibility" coin...
Summary: yes, MySQL has its limitations and issues - and it is not designed to replace Oracle RDBMS, but for smaller/side projects it becomes a solid alternative. As a result for anybody involved with Oracle databases sooner than later it will become a necessity to have a good idea about what MySQL is all about. Back to books, ladies and gentlemen!
P.s. I am aware that Facebook runs on MySQL - and that MySQL can technically support big implementations. But in "the real corporate world" there are terabytes of data managed by RDBMS - and thousands of specialists trained to do it well. For them MySQL can augment their tech stack, but cannot replace it.