Failover Data Source for when ETL is running

[gohabsgo]

Hey Folks,
We're a global shop so would like to have 24/7 availability of our reporting needs met.  When ETL is running, the DB is offline and so cannot be reported against and we'd like to resolve this, is there a best practice to setting this up?  Should we perhaps define the DW connection with a synonym and have the connection resolve to the current active DW behind the scenes?  Better idea perhaps?

Thanks!
-D

[TomCognos]

Why not simply stage the reporting layer elsewhere. Then either trickle feed the updates to the tables in the staged DB or have a set time when the data is fed across.

Cognos should be setup to dirty read so there shouldn't be any locks on the tables when the reports are active. So it really comes down to why the DB is offline while you update ?