> I have both, domains with just the based simple datatype in its name, e.g.:
>
> D_INT
> D_NUMERIC_15_2
>
> which are NOT NULL in naming convention or their nullable counterparts:
>
> D_INT_NULL
> D_NUMERIC_15_2_NULL
>
> using NULL as domain name prefix.
>
> The second approach is to put semantic into the domain name, e.g.:
>
> D_ZIP_CODE
> D_FIRSTNAME
>
> etc ... Or have special domains for primary/foreign key columns, e.g.:
>
> D_PK
> D_FK
> D_FK_NULL
>

Thanks Thomas, it is a big help.

I think I will bite the bullet and convert to user domains, at least it will make the db more consistent.

Mike