Subject Re: [firebird-support] Oldest transaction far behind...
Author Ann Harrison

>         Oldest transaction      25545713
>         Oldest active           26347481
>         Oldest snapshot         26347481
>         Next transaction        26347482

If this isn't in an FAQ somewhere, it should be. The "Oldest transaction"
is the oldest transaction that is not committed. It may be active, it may
be rolled back, or it may be in limbo - prepared as part of a two-phase
commit and not committed.

It's not active, since you said only one transaction was running on
the system.

If it is rolled back, a sweep will fix it. Firebird undoes the changes of a
transaction that issues a roll back, but if there was a server, operating
system, or hardware crash, transactions will be stuck in a rolled back
state until a sweep.

If it's in limbo, you can resolve it with gfix.

Back when InterBase had only classic mode, and when memory was
a very limited resource, keeping a bitmap of the state of all transactions
between the oldest non-committed and current used a serious amount
of memory and keeping the oldest transaction relatively current was
important. Now, not so much.

Good luck