Re: about call-convention in PostgreSQL programming

"Seung Hyun Jeong" <jeongs@cs.man.ac.uk> writes:
> Relation open_gist(PG_FUNCTION_ARGS)
> {
>    char *index_name = (char *) PG_GETARG_POINTER(0);

You didn't say what datatype your function is declared to accept ...
but there is no Postgres datatype that is identical to a C string.
You have some conversion work to do if you want to, say, produce
a C string from a "text" input.
        regards, tom lane