Thread: OIDs

Kapil Tilwani writes:

> What happens when OIDs overflow?

You might get spurious problems when you are altering your schema (unique
contraint violations on the system catalogs), but those can be overcome by
manually advancing the oid past the area used by the system.

> What are XIDs?

transaction ids

> What if they overflow?

Your database system evaporates.  Seriously.

> Secondly, OIDs are always sequential, right?  Cant they be random....

That would be significantly harder to keep track of.

> I wouldnt like to keep a track (or from anyone finding out) which record came in first...

That wouldn't be very hard to find out without the oids either.

--
Peter Eisentraut   peter_e@gmx.net   http://funkturm.homeip.net/~peter

I would like to make it impossible to be traced as to which record came in
first and which next, however, being sequential reveal that...  How should I
ensure this?

Thanx

----- Original Message -----
From: "Peter Eisentraut" <peter_e@gmx.net>
To: "Kapil Tilwani" <karan_pg_2@yahoo.com>
Cc: <pgsql-general@postgresql.org>
Sent: Saturday, June 30, 2001 9:53 PM
Subject: Re: [GENERAL] OIDs


> Kapil Tilwani writes:
>
> > What happens when OIDs overflow?
>
> You might get spurious problems when you are altering your schema (unique
> contraint violations on the system catalogs), but those can be overcome by
> manually advancing the oid past the area used by the system.
>
> > What are XIDs?
>
> transaction ids
>
> > What if they overflow?
>
> Your database system evaporates.  Seriously.
>
> > Secondly, OIDs are always sequential, right?  Cant they be random....
>
> That would be significantly harder to keep track of.
>
> > I wouldnt like to keep a track (or from anyone finding out) which record
came in first...
>
> That wouldn't be very hard to find out without the oids either.
>
> --
> Peter Eisentraut   peter_e@gmx.net   http://funkturm.homeip.net/~peter
>
>
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Kapil Tilwani writes:

> I would like to make it impossible to be traced as to which record came in
> first and which next, however, being sequential reveal that...  How should I
> ensure this?

If you want cryptographic security you will need to use advanced
algorithms to shuffle your data.  In almost any advanced storage system,
data records will be numbered or incrementally arranged as they come in.
Even if you eliminated the oids (which you could just set to random values
if you wanted), there are still transaction ids and tuple ids, which you
won't be able to get rid of.

--
Peter Eisentraut   peter_e@gmx.net   http://funkturm.homeip.net/~peter