[Info-ingres] Incremental Rollforwarddb

[Roy Hann]

Steve wrote:

> Hi folks
> 
> According to the Ingres documentation, a rollforward with -rollback
> requires all journals since the last checkpoint be present.
> 
> Does "all journals" really mean all journals stretching back to when
> the checkpoint was taken or does it simply mean all journals yet to
> be applied?
> 
> Our DR environments has been in a state of incremental rollforward for
> probably over a year and we only keep several days of journals.

The -rollback flag just controls what happens when the rollforward runs
out of journal records at the end of the process. If there are
uncommitted transactions it rolls them back instead of assuming "future"
journal files would complete the transactions and dispose of them in the
usual way.

If whatever your incremental rollforward is doing is working as you
expect and require, adding -rollback won't stop it working. It may
however cause transactions to be lost that would otherwise have been
recovered in future.

Roy