Re: getTypeIOParam is wrong for domains over array types?

On 3/19/07, Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> wrote:
> In lsyscache.c we have
>
> /*
> * Array types get their typelem as parameter; everybody else gets their
> * own type OID as parameter. (This is a change from 8.0, in which only
> * composite types got their own OID as parameter.)
> */
> if (OidIsValid(typeStruct->typelem))
> return typeStruct->typelem;
> else
> return HeapTupleGetOid(typeTuple);
>
> but it turns out that a domain over an array type has typelem set, and
> so domain_in gets passed the element type instead of the domain's own
> OID, leading to this misbehavior reported by Anton Pikhteryev:
>
> regression=# create domain ddd as name;
> CREATE DOMAIN
> regression=# create table foot(f1 ddd);
> CREATE TABLE
> regression=# copy foot from stdin;
> Enter data to be copied followed by a newline.
> End with a backslash and a period on a line by itself.
> >> dd
> >> \.
> ERROR: type "char" is not a domain
> CONTEXT: COPY foot, line 1, column f1: "dd"
>
> This failure is new in 8.2 --- in prior releases domain_in didn't exist
> and it was correct, indeed necessary, for domains to get exactly the
> same typioparam as their underlying type.
>
> I think probably the right solution is to adjust getTypeIOParam so that
> it only examines typelem for base types (typtype = 'b'). Can anyone
> see a downside to that?

will that skip intermediate check constraints...so that if you have
domain d1 int, d2 d1, d3 d2, and d2 has check constraint on it, will
d2 constraint still get evaluated? or is this only for purposes if
determining type?

merlin