What relational database innovations have there been in the last 10 years

Question

The SQL implementation of relational databases has been around in their current form for something like 25 years (since System R and Ingres). Even the main (loosely adhered to) standard is ANSI-92 (although there were later updates) is a good 15 years old.

What innovations can you think of with SQL based databases in the last ten years or so. I am specifically excluding OLAP, Columnar and other non-relational (or at least non SQL) innovations. I also want to exclude 'application server' type features and bundling (like reporting tools)

Although the basic approach has remained fairly static, I can think of:

• Availability
• Ability to handle larger sets of data
• Ease of maintenance and configuration
• Support for more advanced data types (blob, xml, unicode etc)

Any others that you can think of?

Answer 1

• Hash joins
• Cost-based optimizers (pretty much turned query-writing on its head)
• Partitioning (enables much better VLDB management)
• Parallel (multi-threaded) query processing
• Clustering (not just availability but scalability too)
• More flexibility in SQL as well as easier integration of SQL with 3GL languages
• Better diagnostics capabilities

Answer 2

Analytic functions like RANK

Answer 3

I'm not sure if you want to include even vendor-specific innovations (and nor am I entirely certain that other database engines can't already do this), but SQL Server 2005 adds recursive transact-sql queries to their language. I find them amazingly useful for iterating over hierarchical data. I believe 2008 adds some new functionality related to hierarchical data, but I haven't looked that closely.