Here's my 2 cents worth: if purely from a DB failover, auto standby is good - just remember, you may not get ALL the data over (online redos), but it'll be a quick switchover and config/maintenance is much better now in 8i. Haven't used Oracle Parallel Failover. If from OS, we use Veritas Cluster Server, which is reliable. Also there is SUN Clustering on SUN servers and HP ServiceGuard for HP-UNIX servers that are excellent for OS failover.