Re: PostgreSQL - 'SKYLINE OF' clause added!

Tom,

> My questions about whether to adopt it have more to do with
> cost/benefit.  I haven't seen the patch, but it sounds like it will be
> large and messy; and it's for a feature that nobody ever heard of before,
> let alone one that the community has developed a consensus it wants.
> I'm not interested in adopting stuff just "because DB2 hasn't got it".

OK, to make it a clearer case: we have an increasing user base using 
PostgreSQL for decision support.  One of the reasons for this is that PG is 
the *only* OSDB which does a decent job of DSS.  Adding unique DSS features 
will make PostgreSQL attractive to a lot more DSS application developers, and 
help make up for the things which we don't have yet (parallel query, async 
I/O, windowing functions).  

"Approximate queries" is something with DSS users *want*.  Jim Grey addressed 
this in his ACM editiorial on the databases of the future.  It's something 
that *I* want, and if the Greenplum people aren't speaking up here, it's 
because they're not paying atttention.

Now, I don't know if this Skyline patch is our answer for approximate queries.  
Maybe I should pester Meredith about getting QBE free of its IP issues; it 
certainly looked more flexible than Skyline.  In either case, the code 
probably needs a complete refactor. 

But I think that approximate queries ought to be on our TODO list.

-- 
Josh Berkus
PostgreSQL @ Sun
San Francisco