For the benefit of everyone who is interested but hasn't had the chance to get involved in that process, here is what is currently going on:
- A new standard is currently in the "Final Committee Draft" (FCD) phase, which basically means "beta". The final release is expected in 2011, so you will begin to see mentions of "SQL:2011".
- The new standard will only contain parts 1/Framework, 2/Foundation, 4/PSM, 11/Schemata, 14/XML. The other parts are currently not being developed, which doesn't mean they are dead or withdrawn, but that no one bothers to add things to them at the moment.
- All new features in SQL:2011 will be in the form of optional features. So the level of core conformance is not impacted by the release of a new standard.
- The syntax ALTER TABLE ... ALTER COLUMN ... SET/DROP NOT NULL has been taken into the standard. PostgreSQL has supported that since version 7.3. Coincidence? Not sure.
- Constraints can optionally be set to NO ENFORCE. That means the database system won't enforce them but still assumes they are valid, for example for optimization.
- System-versioned tables: Perhaps the largest new feature, this is a way to make data (rows) visible only during certain times. Some pundits might recall a moral predecessor of this feature labeled SQL/Temporal. I haven't fully analyzed this feature yet, so I'll post later about the details.
- Combined data change and retrieval. PostgreSQL does something like this with RETURNING, but this feature is more elaborate and allows the writing of "delta tables".
- Named arguments in function calls. PostgreSQL 9.0 supports that, but using the syntax foo(3 AS a) instead of what ended up in the standard, foo(a => 3).
- Default values for function arguments. PostgreSQL 9.0 supports that as well.