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 ---------------------------(end of broadcast)--------------------------- TIP 5: don't forget to increase your free space map settings