Re: Help me recovering data

Tom Lane wrote:
> Gaetano Mendola <mendola(at)bigfoot(dot)com> writes:
> > BTW, why not do an automatic vacuum instead of shutdown ? At least the
> > DB do not stop working untill someone study what the problem is and
> > how solve it.
>
> No, the entire point of this discussion is to whup the DBA upside the
> head with a big enough cluestick to get him to install autovacuum.
>
> Once autovacuum is default, it won't matter anymore.

I have a concern about this that I hope is just based on some
misunderstanding on my part.

My concern is: suppose that a database is modified extremely
infrequently? So infrequently, in fact, that over a billion read
transactions occur before the next write transaction. Once that write
transaction occurs, you're hosed, right? Autovacuum won't catch this
because it takes action based on the write activity that occurs in the
tables.

So: will autovacuum be coded to explicitly look for transaction
wraparound, or to automatically vacuum every N number of transactions
(e.g., 500 million)?

--
Kevin Brown kevin(at)sysexperts(dot)com