Re: pg_depend

Bruce Momjian writes:

> Is it? Are we going to record dependency both ways, e.g primary table
> -> foreign table and foreign table -> primary table, or just one of
> them. And when we see we depend on something, do we know always what it
> could be. If I drop a table and I depend on oid XXX, do I know if that
> is a type, function, or serial sequence?

When you drop a table, there are only so many things that could depend on
it:

* rules/views
* triggers
* check constraints
* foreign key constraints
* primary key constraints
* unique constraints
* subtables

including their dependencies. There might be others I forgot but a
finite list can be defined.

When a table is dropped, you scan all of these objects (their system
catalogs) for matches against the table and either do a cascade or
restrict. This is not new, we already do this for indexes and
descriptions, for instance.

--
Peter Eisentraut peter_e(at)gmx(dot)net http://funkturm.homeip.net/~peter