Karel Zak - Zakkr <zakkr(at)zf(dot)jcu(dot)cz> writes:
> I have a question... How PG parser select (build-in) function?
> Check parser function's arguments datetypes only or check returns value
> datetype too (for function searching in system cache ..etc)?
The argument types have to be different. In general, the parser
doesn't *know* what the return type of the function is; it has to
discover that by looking up the function. So you can't have two
functions of the same name unless they differ in number and/or type
of arguments.
regards, tom lane