renaming+recreating table w/default sequence causes dependency seq issue

From: Todd Kover <kovert(at)omniscient(dot)com>
To: pgsql-bugs(at)postgresql(dot)org
Subject: renaming+recreating table w/default sequence causes dependency seq issue
Date: 2012-08-08 00:10:25
Message-ID: 201208080010.q780APDf006070@guinness.omniscient.com
Views: Raw Message | Whole Thread | Download mbox | Resend email
Thread:
Lists: pgsql-bugs


I saw issues around renaming tables and not renaming sequences in the TODO
list but did not see anything about this. Apologies if I missed it.

This is with a 9.1.4 server (enterprisedb download on mac os/x lion) and also
seen on 9.1.3 built from netbsd pkgsrc.

It appears that something is amiss if you try to drop a table that has been
renamed that used to have a default mapping to a sequence:

Given this:
---<snip>---
drop table IF EXISTS foo;
drop table IF EXISTS foo_v26;

create table foo (id serial not null, bar integer );
alter table foo alter column id drop default;

alter table foo rename to foo_v26;

create table foo (id integer not null, bar integer );

alter table foo alter id SET DEFAULT nextval('foo_id_seq');

drop table foo_v26;
---<snip>---

everthing works as expected until the final drop, which says:

jazzhands=> drop table foo_v26;
ERROR: cannot drop table foo_v26 because other objects depend on it
DETAIL: default for table foo column id depends on sequence foo_id_seq
HINT: Use DROP ... CASCADE to drop the dependent objects too.

however...

jazzhands=> \d foo;
Table "public.foo"
Column | Type | Modifiers
--------+---------+--------------------------------------------------
id | integer | not null default nextval('foo_id_seq'::regclass)

jazzhands=> \d foo_v26;
Table "public.foo_v26"
Column | Type | Modifiers
--------+---------+-----------
id | integer | not null

Interestingly, I can drop table foo without any complaints.

It seems like the dependency did not move (it also seems like its
backwards but that's probably all me).

Sadly, if I move setting the default to after I drop the old table, the
sequence goes away, so I am still digging into a work around.

thanks,
-Todd

Responses

Browse pgsql-bugs by date

  From Date Subject
Next Message Craig Ringer 2012-08-08 01:16:18 Fwd: [BUGS] Small bug in psqlodbc-09.01 prevents interoperability with LISTSERV
Previous Message Robert Haas 2012-08-07 20:34:21 Re: event triggers patch breaks with -DCLOBBER_CACHE_ALWAYS