How does Virtuoso handle backups?
Backups can be handled in a variety of ways. Virtuoso has both off-line and on-line incremental backups. Virtuoso’s transaction mechanism is based on keeping a read-only checkpoint plus a transaction log for any committed but non-checkpointed transactions. Virtuoso has an incremental, on-line backup function, which can backup a running database in its checkpoint state without restricting concurrent update activity. Virtuoso records at each checkpoint the pages, which were changed since the last backup. Hence the next backup will only cover pages , which are changed in the checkpoint state since the last backup. Each checkpoint can optionally start a new transaction log, leaving a full audit trail of transaction logs. Having a series of full plus optionally incremental backups up to a certain checkpoint and then the transaction logs consecutive to the last backed up checkpoint will guarantee a full recovery up to the latest transaction committed at the time of failure. The backup functi
