Re: [SQL] Function valid only for one table

[Tom Lane]

Martin Knipper <[EMAIL PROTECTED]> writes:
> I thought about a mixture of object orientation and a normal table
> for a relational database.
> someFunction() is a method for the object/table someTable.

Perhaps you could do what you want with functions accepting table
rowtypes.

        create function someFunction(someTable) returns ...

        select someFunction(t.*) from someTable t where ...
        -- works

        select someFunction(t.*) from anotherTable t where ...
        -- fails

        create function someFunction(anotherTable) returns ...

        select someFunction(t.*) from someTable t where ...
        -- still works

        select someFunction(t.*) from anotherTable t where ...
        -- now calls the second someFunction()

As of existing releases this doesn't scale well to large tables, because
passing a whole table row to a function leaks memory intraquery.  That
is fixed for 7.5 though.

                        regards, tom lane

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