Re: Again, sorry, caching, (Tom What do you think: function

mlw wrote:
> Jan Wieck wrote:
> >
> > mlw wrote:
> > > [...]
> > >
> > > IMHO modifying the function manager to allow the return of a full row, and a
> > > "set of" full rows, answers a LOT of issues I have seen over the years with
> > > PostgreSQL extensibility.
> >
> >     Sure.  Actually I think you'll have an easy project with this
> >     one, because all the work has been done by Tom already.
> >
> >     The function manager isn't the problem any more. It  is  that
> >     you  cannot  have such a "set of" function in the rangetable.
> >     So you have no mechanism to USE the result.
>
> I'm not sure I follow you. OK, maybe I identified the wrong portion of code.
>
> The idea is that the first return value could return an array of varlenas, one
> for each column, then a set of varlenas, one for each column.
>
> Is there a way to return this to PostgreSQL?
   There  is a way to return anything. The problem in PostgreSQL   is to actually USE it.
   Our idea originally was  to  extend  the  capabilities  of  a   rangetable  entry.   Currently,  rangetable  entries
canonly   hold a relation, which is a table or a view. After rewriting,   they are down to real tables only.
 
   But  basically,  a  rangetable  entry  should  just be a row-   source, so that a function returning a  row-set
could occur   there too.
 
   In  order  to avoid multiple calls to the function because of   nestloops and the like, I think when a set function
occursin   a RTE, it's result should be dumped into a sort-tape and that   is used as the row source in the rest of the
plan.


Jan

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