On Tue, 15 Jan 2002, Gavin Sherry wrote:
> On Mon, 14 Jan 2002, Tom Lane wrote:
>
> > Martin Renters <martin@datafax.com> writes:
> > > Should the permissions of a deleted user get assigned to a new user
> > > as in the example below?
> >
> > That can happen, since the default "usesysid" assignment is "max
> > existing usesysid + 1". If you delete the last user then their sysid
> > becomes a candidate for reassignment. This is not real good, but fixing
> > it isn't that high on the priority list (and is difficult to do unless
> > we take away the option of hand-assigned sysids ... otherwise we could
> > just have a sequence generator for sysids).
>
> Another slight bug with CreateUser() -- there does not appear to be any
> checking for potential overflow of sysid. The function scans pg_shadow to
> find the largest usrsysid. Once obtained:
>
> /* If no sysid given, use max existing id + 1 */
> if (!havesysid)
> sysid = max_id + 1;
>
Left this bit off:
template1=# create user def with sysid 2147483647;
CREATE USER
template1=# create user def2;
CREATE USER
template1=# create user def3;
ERROR: Cannot insert a duplicate key into unique index
pg_shadow_usesysid_index
template1=# select usesysid from pg_shadow where usename ~ 'def'; usesysid
------------- 2147483647-2147483648
(2 rows)
template1=# select version(); version
---------------------------------------------------------------------PostgreSQL 7.2b4 on i686-pc-linux-gnu, compiled by
GCCegcs-2.91.66
(1 row)
template1=#
Gavin
