Disclaimer 1: The definition of the word "cool" is entirely subjective, and is not intended to imply significance, market impact, or anything other than what normal people generally understand "coolness" to be.
Disclaimer 2: I'm an RDBMS guy, and a reporting RDBMS guy at that. Hierarchical and object databases may be cooler than relational databases, but I don't know anything about them yet. I'm sure there are some cool OLTP-related developments I'm not thinking of too. Please don't complain about my lack of scope - it's a known deficiency.
Without further ado...
- Netezza - A massively parallel database is cool enough. But a specialized hardware appliance that I can plug my own functions into? Please. How do you top that?
Yes, yes, I know, Teradata has been doing the whole MPP database things for years. But NZ made it more affordable and a pleasure to work with. Can't say either of those things about Teradata.
- Vertica - Sybase has been doing the column oriented thing for a while, but much like Netezza made MPP practical, Vertica makes column orientation practical. Doing it with intelligent compression and whitebox hardware, in an MPP arrangement no less, is icing on an already tasty cake. If this were the 'most significant reporting developments list' this would probably be at the top. Even so, the sheer power and elegance of the things makes it incredibly cool.
- SQLite - A full featured, embeddable, easily extensible database engine in a 500k library? Free?! Unbelievable. I've gotten more use out of SQLite than just about any tool except my text editor, I think.
- The CASE function - If I had a nickel for every problem I've solved using the CASE function, I could probably put my kids through college with the money.
- Oracle for Linux - Oracle's support for Linux may have done more for the credibility of Linux in the corporate world than anything else. Plus, as a long-time Linux user, the availability of Oracle on Linux put me one very large step further away from Windows, which made me pretty happy.
What's on your list? What did I overlook? I'd love to hear others' opinions and extend/refine this list, so please, post a comment or send me an email.