Dependency Tracking function

Question

I just wonder if anyone knows how to automatize views creation after running DROP ... CASCADE? Now I\'m trying to drop view at first with classic DROP VIE

Answer 1

Table pg_depend contains all necessary informations, but it is not so easy to interpret them. Here you have sketch recursive function to retrieve dependencies of pg_class object in text format. You can tune up the function to your needs (and show us results:).

create or replace function dependency
    (class_id regclass, obj_id regclass, obj_subid integer, dep_type "char")
returns setof text language plpgsql as $$
declare
    r record;
begin
    return query 
        select pg_describe_object(class_id, obj_id, obj_subid)
            || ' ('|| dep_type|| ')';
    for r in
        select classid, objid, objsubid, deptype
        from pg_depend
        where class_id = refclassid
        and obj_id = refobjid
        and (obj_subid = refobjsubid or obj_subid = 0)
    loop
        return query select dependency(r.classid, r.objid, r.objsubid, r.deptype);
    end loop;
end; $$;

use:

select dependency('pg_class'::regclass, 'my_view'::regclass, 0, ' ');
select dependency('pg_class'::regclass, 'my_table'::regclass, 0, ' ');