Zoltan Boszormenyi írta:
Simon Riggs írta:
On Tue, 2008-03-25 at 09:08 -0700, Steve Crawford wrote:
Simon Riggs wrote:
RESTART IDENTITY will reset the SERIAL sequences back to the original
start value.
Assuming this feature were to be added....
In cases where the same sequence has been used across multiple
tables, what will be the appropriate response when a user attempts
to TRUNCATE one of those tables with RESTART IDENTITY?
Well, I'm suggesting it as a TODO item, based on the standard. It would
be for whoever took this up to unravel that.
Since that's a weak answer, I'd say it should only reset sequences that
have been placed there automatically through the use of SERIAL or
BIGSERIAL datatypes.
All of them? PostgreSQL allow multiple SERIALs to be present,
the standard allows only one IDENTITY column in a table.
And what about this case below?
CREATE TABLE t1 (id1 serial, ...);
ALTER SEQUENCE seq_t1_id1 RESTART WITH 5432 CYCLE;
or the equivalent
CREATE SEQUENCE seq_t1_id1 START WITH 5432 CYCLE;
CREATE TABLE t1 (id1 serial, ...);
of course
CREATE TABLE t1 (id1 integer, ...);
ALTER SEQUENCE seq_t1_id1 OWNED BY t1.id1;
PostgreSQL doesn't keep the START WITH information.
But it should to perform a "restart" on the sequence,
using the minval in this case wouldn't be correct.
--
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Zoltán Böszörményi
Cybertec Schönig & Schönig GmbH
http://www.postgresql.at/
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