Jan Wieck wrote:
>
> Another detail I'm missing now is a new, really defined
> interface for type input/output functions. The fact that they
> are defined taking one opaque (yepp, should be something
> different as already discussed) argument but in fact get more
> information from the attribute is ugly.
Can we currently return a list of the same type ?
I guess we can, as lists (or arrays) are fundamentl types in
PostgreSQL, but I'm not sure.
I would like to define aggregate functions list() and set()
Could I define then just once and specify that they return an array
of their input type ?
Half of that is currently done for count() - i.e. it can take any
type of argument, but I guess the return-array-of-input-type is more
complicated.
Also (probably off topic) how hard would it be to add another type
of aggregate funtions tha operate on pairs of values ?
I would like to have FOR_MIN and FOR_MAX (and possibly MIN_MIN and
MAX_MAX) functions that return _another_ field from a table for a
minimal value in one field.
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Hannu