Learn when to adjust database generation numbers.
RepAgent for a primary database places the database generation number in the high-order 2 bytes of the qid that it constructs for each log record it passes to the Replication Server.
The remainder of the qid is constructed from other information that gives the location of the record in the log and also ensures that the qid increases for each record passed to Replication Server.
The requirement for increasing qid values allows Replication Server to detect duplicate records. For example, when a RepAgent restarts, it may resend some log records that Replication Server has already processed. If Replication Server receives a record with a lower qid than the last record it processed, it treats the record as a duplicate and ignores it.
If you are restoring a primary database to an earlier state, increment the database generation number so that the Replication Server does not ignore log records submitted after the database is reloaded. This step applies only if you are loading a primary database from dumps or loading from coordinated dumps.
If you are replaying log records, increment the database generation number only if RepAgent previously sent the reloaded log records with the higher generation number. This situation arises only if you have to restore the database and log to a previous state for the first failure and then later replay the log due to a second failure.