>Oldest active 105
>Next transaction 12680

This means that transaction 105 is still open, and that Firebird have not
been able to delete any record versions since it was opened. If all
transactions between the two numbers above are updates of 2038 records, you
have something like 25 million records (12500*2000) waiting for this
transaction to end before they can be deleted (OK, strictly speaking they
are the different versions of your 2038 records). I guess they could
consume some space...

Note that transaction 105 doesn't have to be a transaction that modifies
any data, even selects require a transaction to run.

Set