How to drop sequence?

Hi,

I have table:

# \d category;
category_id | integer | not null default
nextval('public.category_category_id_seq'::text)
category_name | character varying(100) | not null
Indexes: category_pkey primary key btree (category_id)

My goal is to remove sequence from category_id column and remove it after
from DB.

First I tried:

DROP SEQUENCE category_category_id_seq - fails saying that table category
column category_id uses it

Than I tried:

ALTER TABLE category ALTER COLUMN category_id DROP DEFAULT;

Now category_id column is shown as integer not null only but :

DROP SEQUENCE category_category_id_seq - fails saying that table category
column category_id uses it again

Any suggestions?

Thank you,

Igor