(See this post for part 1)
Okay, time for a DBMS reality check.
First, IBM, Microsoft, and Oracle collectively control, by most estimates, around 85% of the commercial DBMS market (which was generally assumed to be ~$21B in 2007). Sun's $1B acquisition of MySQL AB earlier this year also suggests that perhaps there's still some mileage left in the DBMS market as we've known it for the last decade or two.
Second, DBMS and RDBMS (relational DBMS) are not 1:1; the latest DBMS products from IBM, Microsoft, and Oracle, in particular, manage multiple database models (e.g., relational, XML, files, streaming, and OLAP). And they can do so with much lower total administration/license/etc. costs, compared with the alternative of using "best-of-breed"/specialized products for each database model domain.
Some architectural diagrams of what this looks like, when the bits hit the disk:
(Wow, these vendors are so fiercely competitive, they even use the same general color schemes:)...)
XQuery, the subject of my next post in this series, is a game-changer that brings significant potential for the DBMS leaders to leapfrog specialized XML content/data management systems (and SQL certainly isn't going away, nor are proprietary DBMS programming languages such as Transact-SQL or PL/SQL).
With XQuery and full-fidelity XML database model management in the leading DBMSs, it will also be possible for enterprises to shift some of their document management/content management infrastructure to DBMSs (rather than continuing to rely on traditional, proprietary specialized alternatives). This means enterprises will be able to have fewer moving parts in their data management infrastructure, vastly simplified data/document (a.k.a. structured/unstructured information) integration/synchronization opportunities, and fewer product licenses to renew each year.
The specialized vendors will also continue to have considerable market opportunities for the immediate future, of course, as enterprises don't undertake DBMS upgrades lightly, and some edge cases will remain out of the scope of the leading DBMSs for a while (e.g., petabyte XML document management scenarios), but for the most part it's likely the next generation of market leaders in the enterprise DBMS market will look a lot like the current generation, perhaps with relative market share changes along the way.
To close by addressing the questions from part 1 of this post:
- It is not the end of the road for RDBMSs as we've known them for the last ~25 years; they're morphing to become multi-database model DBMSs, and they're likely to gain rather than lose momentum over the next few years.
- Hang on to those SQL books; you're going to need them. The relational database model is still the most robust and powerful general-purpose database model, and it has significant synergy with XML (as the leading document model).
- It would indeed be prudent to also invest some time and attention in learning more about XML (data and documents), along with XQuery (which will be relatively easy to learn, if you've already mastered SQL). Burton Group has a bunch of research content in these domains, incidentally...
- Specialized XML data management systems are gaining momentum, but don't bother exploring IMS, IDMS, or other pre-relational systems for career enhancement potential, and it is still not the case that "everything is an object", so don't expect OODBMSs to rise from their graves anytime soon. Some object database systems are being re-treaded and repositioned as XML database systems, but you probably want to look very closely before betting your next app on XML systems that aren't fundamentally designed to support XQuery (as opposed to bolting XQuery support on top of an existing object database system).
- Don't worry about Larry Ellison's financial stability; he's probably going to be on that Forbes list for the foreseeable future...
The next DMS 2008 theme: XQuery
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