Обсуждение: BUG #3224: Dump: missing schema name for sequence in a "DEFAULT nextval" specification

The following bug has been logged online:

Bug reference:      3224
Logged by:          Gabriele Bartolini
Email address:      g.bartolini@comune.prato.it
PostgreSQL version: 8.2.3
Operating system:   GNU/Linux ( 2.6.9-42.0.2.ELsmp )
Description:        Dump: missing schema name for sequence in a "DEFAULT
nextval" specification
Details:

Here is the example. I have a schema called 'dimensions' where I have a
hosts_2006_seq sequence and a hosts_2006 table, defined as follows:

CREATE SCHEMA dimensions;
CREATE SEQUENCE dimensions.hosts_2006_seq;
CREATE TABLE dimensions.hosts_2006
(
  id_host integer NOT NULL DEFAULT
nextval('dimensions.hosts_2006_seq'::regclass),
  host character varying(255) NOT NULL DEFAULT ''::character varying,
  CONSTRAINT hosts_2006_pkey PRIMARY KEY (id_host)
);

As you can see I want the 'nextval' function to get the sequence value from
the proper table in the 'dimensions' schema, and that works fine.

However, when I issue a pg_dump or pg_dumpall command, here is what I get:

SET search_path = dimensions, pg_catalog;
CREATE SEQUENCE hosts_2006_seq;
CREATE TABLE hosts_2006 (
    id_host integer DEFAULT nextval('hosts_2006_seq'::regclass) NOT NULL,
    host character varying(255) DEFAULT ''::character varying NOT NULL,
);

This causes the 'nextval()' to go and look for the proper sequence according
to the search path and not in  an absolute way.

I don't know whether this can be considered a bug, but it definitely created
a few problems on my scenario.

Thank you.

Ciao,
Gabriele

"Gabriele Bartolini" <g.bartolini@comune.prato.it> writes:
> However, when I issue a pg_dump or pg_dumpall command, here is what I get:

> SET search_path = dimensions, pg_catalog;
> CREATE SEQUENCE hosts_2006_seq;
> CREATE TABLE hosts_2006 (
>     id_host integer DEFAULT nextval('hosts_2006_seq'::regclass) NOT NULL,
>     host character varying(255) DEFAULT ''::character varying NOT NULL,
> );

This is not a bug: the regclass constant will be recreated the same as
it was before.

            regards, tom lane

Hi Tom,

   thanks for the answer. However, I still cannot understand why the 'dimen=
sions' schema has disappeared from the dump of the sequence. I will do furt=
her investigation and let you know.

Ciao,
Gabriele

P.S.: Would you think of coming to the Italian PostgreSQL Day in July? I am=
 one of the main organisers of the event.

-----Messaggio originale-----
Da: Tom Lane [mailto:tgl@sss.pgh.pa.us]
Inviato: ven 13/04/2007 17.15
A: Gabriele Bartolini
Cc: pgsql-bugs@postgresql.org
Oggetto: Re: [BUGS] BUG #3224: Dump: missing schema name for sequence in a =
"DEFAULT nextval" specification=20
=20
"Gabriele Bartolini" <g.bartolini@comune.prato.it> writes:
> However, when I issue a pg_dump or pg_dumpall command, here is what I get:

> SET search_path =3D dimensions, pg_catalog;
> CREATE SEQUENCE hosts_2006_seq;
> CREATE TABLE hosts_2006 (
>     id_host integer DEFAULT nextval('hosts_2006_seq'::regclass) NOT NULL,
>     host character varying(255) DEFAULT ''::character varying NOT NULL,
> );

This is not a bug: the regclass constant will be recreated the same as
it was before.

            regards, tom lane

Gabriele Bartolini wrote:
> Hi Tom,
>
>    thanks for the answer. However, I still cannot understand why the
>    'dimensions' schema has disappeared from the dump of the sequence.
>    I will do further investigation and let you know.

It disappeared because it's not necessary.  The search_path setting just
above makes sure that it is restored correctly.


--
Alvaro Herrera                                http://www.CommandPrompt.com/
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