Greetings,

We are trying to utilise a NetApp filer's snapshot feature to enable rapid recovery in an Oracle DB environment.

We are aware of the www.netapp.com/tech_library/3049TR document which covers the basics. The intention is to use the hot backup alternative to create several snapshots throughout the day to provide maximum coverage. Both Oracle 8 and 8i are in use. I have 2 questions :-

1) The TR defines a sequence in which all tablespaces are placed into hot backup mode. It has been suggested that this step might take an extended period of time. Our tests to date have been on relatively small data volumes and the "ALTER TABLESPACE <name> BEGIN BACKUP;" steps have been almost instantaneous. Is it likely that this step would end up taking longer (say tens of minutes) for large DBs ?

2) The system has been set up so that each "customer data set" is defined as a separate schema, many of which are contained within a single database. Each schema contains one or more data files, but these only contain data related to their own schema and not other schemas. The idea here is that if it was necessary to recover data related to one customer, it should be possible to do this without taking any other customer tablespaces offline. During testing we have found that recovering the entire snapshot (with all data files from all schemas) works fine. But when we have recovered only the single datafile related to one schema, we have run into problems. I feel we may be overlooking some basic issue here. Any advice would be welcome.

regards,

John Hope-Bailie

Source Consulting, South Africa email: johnhb@sourceconsulting.co.za