Re: array of domain types

On Jun 1, 2016, at 4:37 PM, Thom Brown wrote:

On 1 June 2016 at 14:20, Konstantin Knizhnik <k.knizhnik@postgrespro.ru> wrote:

I wonder why domain types can not be used for specification of array element:

create domain objref as bigint;
create table foo(x objref[]);
ERROR:  type "objref[]" does not exist
create table foo(x bigint[]);
CREATE TABLE

Is there some principle problem here or it is just not implemented?

It's not implemented, but patches welcome.
 

Thom

The patch is trivial:  just use typbasetype in get_array_type if typtype is TYPTYPE_DOMAIN:

diff --git a/src/backend/utils/cache/lsyscache.c b/src/backend/utils/cache/lsyscache.c

index cb26d79..ecfbb20 100644

--- a/src/backend/utils/cache/lsyscache.c

+++ b/src/backend/utils/cache/lsyscache.c

@@ -2486,7 +2486,18 @@ get_array_type(Oid typid)

        if (HeapTupleIsValid(tp))

        {

                result = ((Form_pg_type) GETSTRUCT(tp))->typarray;

-               ReleaseSysCache(tp);

+               if (result == InvalidOid && ((Form_pg_type) GETSTRUCT(tp))->typtype == TYPTYPE_DOMAIN) {

+                       typid = ((Form_pg_type) GETSTRUCT(tp))->typbasetype;

+                       ReleaseSysCache(tp);

+                       tp = SearchSysCache1(TYPEOID, ObjectIdGetDatum(typid));

+                       if (HeapTupleIsValid(tp))

+                       {

+                               result = ((Form_pg_type) GETSTRUCT(tp))->typarray;

+                               ReleaseSysCache(tp);

+                       }

+               } else { 

+                       ReleaseSysCache(tp);

+               }

        }

        return result;

 }

Any problems with it?