Re: 4 billion record limit?

> This implies they do wrap around.  So they are reused?  Chris said no, but
> you're saying yes.
>
> (Maybe they wrap around "by accident", by adding one to MAXINT, which will
> give zero on an unsigned int, I believe.  Will the system choke on zero?
> Has anyone tested this wraparound?)
>
> I will not have 4 billion records in one table or even one database.  But
> on a large server with many databases, it is conceivable to have 4 billion
> records on one machine.  With a lot of insert/delete activity, over a few
> years, it is certainly conceivable to have 4 billion inserts.  If the oids
> don't wrap, I have a problem.  I can ignore it for a long time, but it
> will loom, like Y2K.  :-)
>
> Even if they do wrap, if I have some old records lying around with a low
> OIDs, they will trip me up.  Like you said, these are "the outer limits",
> but I'm thinking ahead.
>
> Someone suggested in private that I pg_dump/restore all my data to
> "repack" the oids which start around 1700 on a fresh database.  Thanks for
> that idea.  Also thanks, Tom, for the sanity check Re: terabytes of data
> with 4 billion records.  It's still possible, especially in coming years.
> It would be a big feather in PG's cap to "fully support" 64-bit platforms
> such as IRIX and Solaris (finally) and, coming soon to a theater near you,
> Linux on IA-64.
>

I have added this to the FAQ.  Seems people are concerned enough to
warrant it:

OIDs are stored as 4-byte integers, and will overflow
at 4 billion. No one has reported this every happening, and we plan to
have the limit removed before anyone does.<P>

--
  Bruce Momjian                        |  http://candle.pha.pa.us
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