Christian Kaufmann wrote:

>
> when I run statistics on my database, I get the following information.
> For me it's not clear, why "oldest transaction" is so far behind. When
> I read the stats, there was no application with an open connection anymore.
> ...

Oldest transaction 53823074

> Oldest active 56024312
> Oldest snapshot 56024312
> Next transaction 56024313

The oldest transaction is the oldest transaction that did not commit,
often called the oldest interesting transaction. It probably rolled
back. All records created by older transactions are visible and their
transaction state does not need checking. Records created by this
transaction and later ones may have been rolled back but not yet
removed from the database, so their state must be checked. Clearing
out old rolled back records can improve performance.

gfix -sweep removes old records and resets the value of the oldest
interesting transaction which is stored on the database header page.

Cheers,

Ann