> [EMAIL PROTECTED] writes: >> I think that is sort of arrogant. Look at Oracle, you can give the >> planner >> hints in the form of comments. > > Arrogant or not, that's the general view of the people who work on the > planner. > > The real issue is not so much whether the planner will always get things > right --- it won't, and no one imagines that it will ever be perfect. > The real issue is that we have limited manpower, and designing and > implementing a useful hint facility is a nontrivial project. (Not to > mention that maintaining such a thing in the face of frequent, > fundamental changes to the underlying planner and executor capabilities > would be an outright nightmare.) > > The people who are actually doing the work think their time is more > usefully spent on improving the planner's intelligence than on devising > ways to override it. >
I know I come on strong, and I know I'm probably irritating in many ways, however, I have been a PostgreSQL user since just after it was named postgreSQL from Postgres95. I've seen a lot of changes, and almost all of them have been quite good. I have over 10 years of using it on various projects. While I have not been lucky enough to get a gig in which I could contribute more, I do try to contribute and sometimes it is quite difficult. The one thing that I think you guys miss is actually using PostgreSQL in some projects where the company and the deliverables don't give a rat's ass about whether you use PostgreSQL or Oracle or something else. Over the years I have beat my head against the walls suggesting features, most of which eventually have come to PostgreSQL, but every one was a fight. I have some well founded opinions about PostgreSQL hard earned from real world situations. Agree or not, I have experience with this database and I have hit many of its short comings. One consistent problem is the planner not being able to handle this or that scenario. At this stage, the *best* way to improve the planner is to add the ability to place hints in the plan. It *is* good enough for 90% of the types of queries you would ever want to do. I am dubious that you can get it demonstrably better in the last 10% or so without making it worse. Simple hints would go a HUGE way to improving the last 10%. Many of the "Why doesn't PostgreSQL use my index" questions would go away. Most of the time Tom spends looking at people's pg_stats info would drop. It would actually save time. As a PostgreSQL user, I can tell you with 100% confidence, if I had this tool, I could do my job easier. I can also tell you that while I have genuine appreciation for the current quality of the planner, I still would like to be able to tailor queries specifically to test various approaches for performance reasons. ---------------------------(end of broadcast)--------------------------- TIP 8: explain analyze is your friend
