Re: BUG #15572: Misleading message reported by "Drop functionoperation" on DB with functions having same name

On 2019-Jan-04, David Rowley wrote:

> It's not really that clear to me that doing that would be any more
> correct than the alternative.

I think it would be.  Specifying a function without params works only if
it's unambiguous; if ambiguity is possible, raise an error.  On the
other hand, lack of IF EXISTS is supposed to raise an error if the
function doesn't exist; its presence means not the report that
particular error, but it doesn't mean to suppress other errors such as
the ambiguity one.

I'm not sure what's a good way to implement this, however.  Maybe the
solution is to have LookupFuncName return InvalidOid when the function
name is ambiguous and let LookupFuncWithArgs report the error
appropriately.  I think this behavior is weird:

    /*
     * When looking for a function or routine, we pass noError through to
     * LookupFuncName and let it make any error messages.  Otherwise, we make
     * our own errors for the aggregate and procedure cases.
     */
    oid = LookupFuncName(func->objname, func->args_unspecified ? -1 : argcount, argoids,
                         (objtype == OBJECT_FUNCTION || objtype == OBJECT_ROUTINE) ? noError : true);

-- 
Álvaro Herrera                https://www.2ndQuadrant.com/
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