Original User: vangelo
There isn't any failover capability in ArcSDE (as that seven year old PDF correctly states).
Oracle's high availability enviroment is managed by RAC (Real Application Cluster). Install/
config of RAC is outside the scope of the ArcGIS forums, but the generic description is correct --
there are two (or more) servers accessing one external disk store, which is stored in common
for active/passive or active/active use.
Oracle also has a feature called Data Guard, which permits log shipping from a primary database
to have active/passive or active/active databases with two (or more) disk stores. More exotic forms
can include Data Guarding RAC nodes (many servers, many disk stores).
Since that whitepaper was released, ArcGIS has introduced its own replication capability, which
is captured at the ArcGIS level and doesn't use ArcSDE (beyond versioning).
- V