sql - Deleting a table in PostgreSQL without deleting an associated sequence -

i have table, foo. purposes of quick upgrade/deploy of site, made new table, tmp_foo, contain new data, doing:

create table tmp_foo (like foo including constraints including defaults including indexes); 

now each table has pk id column looks like:

   column    |         type          |                                modifiers                                  -------------+-----------------------+--------------------------------------------------------------------------  id          | integer               | not null default nextval('foo_id_seq'::regclass) 

the important point both tables rely on exact same sequence, foo_id_seq. there no tmp_foo_id_seq. seems ok purposes.

after this, loaded tmp_foo new data , renamed tables tmp_foo took on real foo, , original foo became foo_old. try drop foo_old:

db=> drop table foo_old ; error:  cannot drop table foo_old because other objects depend on detail:  default table foo_old column id depends on sequence foo_id_seq 

fair enough, id column default still depends on sequence.

db=> alter table foo_old alter column id drop default; 

here's kicker.

db=> drop table foo_old ; error:  cannot drop table foo_old because other objects depend on detail:  default table foo column id depends on sequence foo_id_seq 

so foo_old no longer has visible dependency on sequence, yet still tries drop sequence along table (and won't because new table depends upon it).

so question two-part:

1. why sequence still linked old table?
2. is there way around doesn't involve making new table depend on new or different sequence (if help)?

(on postgresql 8.4)

try this:

 alter sequence foo_id_seq owned none 

then should able drop table.

to retrieve "owner" of sequence use following query

 select s.relname sequence_name,          n.nspname sequence_schema,          t.relname related_table,         a.attname related_column    pg_class s, pg_depend d, pg_class t, pg_attribute a, pg_namespace n    s.relkind     = 's'      , n.oid         = s.relnamespace      , d.objid       = s.oid      , d.refobjid    = t.oid      , (d.refobjid, d.refobjsubid) = (a.attrelid, a.attnum)