On Fri, Feb 03, 2006 at 08:33:23AM -0500, Chris Campbell wrote: > On Feb 3, 2006, at 02:09, Tino Wildenhain wrote: > > >Well if the view does not suit your needs, why dont you use an > >set returnung function instead? Inside it you can do all the magic > >you want and still use it similar to a table or view. > > That's what I'm currently doing (as explained in the first message in > the thread). But the function is a "black box" to the planner when > the query is executed -- I'd like the planner to be able to combine > the query inside the function with the outer calling query and plan > it as one big query. Like it does with views. Thus, "views with > arguments." > > We're certainly not deficient in this area (set-returning functions > fill the need quite well), but a feature like this would go even > further in terms of ease-of-use and performance.
Hmm, we actually do inline SQL functions under certain situations, but only for "simple" queries (see inline_function in optimizer/util/clauses.c). One approach would be to expand that function to inline more complicated things. > Benefits of "views with arguments" versus functions: > > * Better query execution performance because the planner can plan the > whole query (rewriting the original query to replace references to > the view with the view's definition -- this is how views work today) Well, the inlining would acheive the same effect. > * PostgreSQL-tracked dependancies: views create dependencies on the > relations they reference -- functions do not Technically a bug. We should be tracking dependancies for functions anyway. > * Don't have to manually maintain a composite type for the return value This is a good point. Though with syntactic sugar you could work around this too... Have a nice day, -- Martijn van Oosterhout <kleptog@svana.org> http://svana.org/kleptog/ > Patent. n. Genius is 5% inspiration and 95% perspiration. A patent is a > tool for doing 5% of the work and then sitting around waiting for someone > else to do the other 95% so you can sue them.
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