Обсуждение: BUG #1316: Alter Name of a Serial Field won't change the corresponding SEQUENCE name

The following bug has been logged online:

Bug reference:      1316
Logged by:          Hongyi Gao

Email address:      admin@listfusion.net

PostgreSQL version: 7.4.5

Operating system:   SuSe Linux 9

Description:        Alter Name of a Serial Field won't change the
corresponding SEQUENCE name

Details:

Alter Name of a Serial Field won't change the corresponding SEQUENCE name
--------------------------------------------------------
say we had a table:

atable (field1 Serial)

it implies to create a sequence:  atable_field1_seq

if I alter table atable alter field1 rename to field2

it becomes atable(field2 Serial)
however, the sequence stays: atable_field1_seq
it's not tablename_fieldname_seq any more
----------------------------------------------------

This will cause problem when we restore a backup:
....
NOTICE: create table atable implies create a sequence atable_field2_seq ...
(here it defaults to tablename_fieldname_seq again)
...
SET SEQUENCE atable_field1_seq ... (here it still tries to restore the
actually sequence we used)
since it's not created, it will fail. And the value of atable_field2_seq is
NOT set !)
this will ruin the whole field.

The same thing may happen if you change the name of a table that has serial
field(s).


Regards,

Hongyi

"PostgreSQL Bugs List" <pgsql-bugs@postgresql.org> writes:
> if I alter table atable alter field1 rename to field2
> it becomes atable(field2 Serial)
> however, the sequence stays: atable_field1_seq
> it's not tablename_fieldname_seq any more

It's intended to do that.

> This will cause problem when we restore a backup:

pg_dump in 8.0 has a workaround for this.

            regards, tom lane