Обсуждение: Moving sequences to another schema
I'm still playing around with the ALTER OBJECT SET SCHEMA stuff. I managed to alter indexes and constraints as well for tables, but with SERIAL sequences there is one little problem: When altering a sequence created by a SERIAL column type (i do this by examining pg_depend to avoid moving any other sequences that are 'foreign'), i need to recreate the default expression for the SERIAL column (stored in pg_attrdef.adbin). Is there an API to do that, or do i have to recreate the executable expression tree from scratch? Or am i missing something completely... TIA -- Bernd
On Tue, Jun 28, 2005 at 01:43:27AM +0200, Bernd Helmle wrote: > When altering a sequence created by a SERIAL column type (i do this by > examining pg_depend to avoid moving any other sequences that are > 'foreign'), i need to recreate the default expression for the SERIAL column > (stored in pg_attrdef.adbin). Is there an API to do that, or do i have to > recreate the executable expression tree from scratch? Or am i missing > something completely... I think this is done by AddRelationRawConstraints. You'd have to get the parsetree of the default expression. I think you could get that by applying raw_parser() to pg_attrdef.adsrc. -- Alvaro Herrera (<alvherre[a]surnet.cl>) "The Postgresql hackers have what I call a "NASA space shot" mentality.Quite refreshing in a world of "weekend drag racer"developers." (Scott Marlowe)
> When altering a sequence created by a SERIAL column type (i do this by > examining pg_depend to avoid moving any other sequences that are > 'foreign'), i need to recreate the default expression for the SERIAL > column (stored in pg_attrdef.adbin). Is there an API to do that, or do i > have to recreate the executable expression tree from scratch? Or am i > missing something completely... Does ALTER TABLE/RENAME code help you? You can rename sequences with that... Chris
Alvaro Herrera <alvherre@surnet.cl> writes:
> I think this is done by AddRelationRawConstraints. You'd have to get
> the parsetree of the default expression. I think you could get that by
> applying raw_parser() to pg_attrdef.adsrc.
Not adsrc --- that's not trustworthy.
In practice I think you could just assume you know what the default
expression ought to be, and store a new one without looking at the old.
regards, tom lane
--On Dienstag, Juni 28, 2005 09:38:56 +0800 Christopher Kings-Lynne <chriskl@familyhealth.com.au> wrote: > Does ALTER TABLE/RENAME code help you? You can rename sequences with > that... Hmm, that doesn't cover pg_attrdef.adbin. I think the best way is to create the default expressions from scratch, as Tom already mentioned. -- Bernd
--On Dienstag, Juni 28, 2005 02:01:33 -0400 Tom Lane <tgl@sss.pgh.pa.us> wrote: > Not adsrc --- that's not trustworthy. > Yes, that's documented in the docs, too. > In practice I think you could just assume you know what the default > expression ought to be, and store a new one without looking at the old. I think i'll go for that (need to figure out how to do that first, but it shouldn't be so hard). Whats the least that should go to -patches for feature release on 1 July (only to know, if i can hold timeline or not).?? -- Bernd
Bernd Helmle <mailings@oopsware.de> writes:
> Whats the least that should go to -patches for
> feature release on 1 July (only to know, if i can hold timeline or not).??
Something reasonably complete, working, credible. We'll cut you slack
on documentation changes and regression tests, and if it has a bug or
three that's what beta testing is for; but it has to at least look like
it will work.
regards, tom lane
--On Dienstag, Juni 28, 2005 01:43:27 +0200 Bernd Helmle <mailings@oopsware.de> wrote: > When altering a sequence created by a SERIAL column type (i do this by > examining pg_depend to avoid moving any other sequences that are > 'foreign'), i need to recreate the default expression for the SERIAL > column (stored in pg_attrdef.adbin). I currently recognized that a SERIAL column doesn't only create an implicit sequence, it creates an implicit composite type with the same name, too. I think this is the same for CREATE SEQUENCE? -- Bernd
On Jun 30, 2005, at 8:13 PM, Bernd Helmle wrote:
> I currently recognized that a SERIAL column doesn't only create an
> implicit sequence, it creates an implicit composite type with the
> same name, too. I think this is the same for CREATE SEQUENCE?
Sequences are just special types of tables. All tables have a
corresponding composite type, so sequences do as well.
CREATE TABLE foo (foo_id serial); is a shorthand for
CREATE SEQUENCE foo_foo_id_seq;
CREATE TABLE foo (foo_id integer default nextval
('foo_foo_id_seq'::text));
Using SERIAL implies CREATE SEQUENCE.
Does this help?
Michael Glaesemann
grzm myrealbox com