Hi Oracle 10g2 (data warehouse) I thought I would ask peoples' thoughts on the following. I have setup our database whereby the index tablespace and data tablespace are separate. This is not for performance reason only for ease of maintenance. We are being advised by the SAN provider to use the following RAID layout Archive redo Logs - RAID 10 Redo Logs - RAID 10 Temp tablespace - RAID 10 Undo tablespace - RAID 10 Index tablespaces - RAID 10 System tablespace - RAID 5 Data tablespaces - RAID 5 Redo logs / Temp tablespace I agree with. To use RAID 5 for data, I understand there is a write performance hit but this is a data warehouse so should be ok (Ideally I would like that RAID 10 as well). But to have the index tablespace on RAID 10 and data tablespace on RAID 5 I found that strange. When I asked the reason why I was give the response 'that is what Oracle recommends'. Has anyone heard this before? Rob