Commit, don't rollback.

Start app
Connect to DB
Swipe
start tx
do your selects
commit
back to swipe
disconnect DB
Stop app


Oldest transaction = oldest transaction that is commited => limbo, rollback,
active
Oldest Active = oldest transaction thatis active (can't remember if this
includes limbo)
Oldest Snapshot = oldest active tx that is using the transaction isolation
of snapshot, i.e. the DB needs to maintain complete commited data at the
time this tx started.

JAC.

> A time keepping program runs 24 hours a day to capture
> time in/out of workers, when user swipes his card, the program
> has to verify a IB server to see if he is a valid user before inserting
> the record to a text file, if we keep a transaction open for validating
> purpose, things are simple but the transaction will be opened all the
> time. if we start the transaction to verify , rollback afterward, this
> has to be done for every swipe which seems an expensive operation,
> any idea?
>
> Also, what does the 'Oldest transaction' mean? thanks.