Re: Class dependencies

Jasen Betts <jasen(at)xnet(dot)co(dot)nz> writes:
> On 2011-01-10, Joel Jacobson <joel(at)gluefinance(dot)com> wrote:
>> Is it safe to assume all objects of a given class can be
>> dropped/created, provided all objects of a list of other classes have
>> already been dropped/created?

>> For instance, is it correct to assume constraints always can be
>> dropped, i.e. no other class (nor other constraints) can depend on
>> them?

> As I unserstand it a references constraint requires a unique
> constraint on the referred-to expressiom.

Another problem for this type of scheme is circular dependencies.
There are for example circular dependencies between a type and its
I/O functions. pg_dump contains some heuristics for resolving the
kinds of circular dependencies that are known to exist.

regards, tom lane