Yes, the REDO collector too picks up the audit trail where it left off when it was shut down. However, just like all other collectors, it can't collect any audit records that have been deleted on the source before they were collected. So, if it needs to go to archive logs to collect records, and the logs were deleted, they are lost, as expected. However, please keep in mind that, for the most part, the collector should not have to go to the archive logs at all, as it tries to stay current as much as possible. Unless the transaction volume on the source is extremely high, the collector should be collecting from the online logs, not needing the archive logs at all.
The REDO collector does use Streams to capture audit records. There's one capture process running on the source. Capture rules are provisioned to the source using Audit Vault's Audit Policy manager, which lets you easily specify capture rules either globally, per-schema, or per-table. Starting the REDO collector starts the capture and propagate processes on the source, and the corresponding apply process on the AV server. Streams uses LogMiner to mine the REDO logs, whether they are online or archived. As LogMiner passes LCRs from the logs to the capture process, the LCRs are evaluated to see if they match any of the provisioned capture rules. If they are, they are sent over to AV where they are converted into audit records and inserted into the audit repository.
Please note, however, that the LCRs are "pulled" from the redo logs by LogMiner; they are not queued (or "pushed") to Streams. In essence, there's only one copy of the LCR that is stored, and that is in the redo logs (whether online or archived). Streams does not store a separate copy for capture. The whole system acts as a pipeline, with the capture process being the driver. There's no queuing involved at all.
looking at the audit repository, specifically the avsys.av$rads_view and the avsys.audit_event_fact, how can you determine if the row entry was collected by the REDO_COLL, the DBAUD, or the OSAUD collectors?