When we plan EMC Symmetrix Virtual Provisioning for Oracle database thin pool, we can use:
3. Thin device preallocation
Can anyone explain how 'Thin device preallocation' work with 'Oversubscription' and 'Undersubscription'?
Yes, Saty, I did read this white paper, but only some simple words like 'thin device preallocation can work with oversubscriptiona and undersubscription to reserve space for database......'.
For Oversubscription, since Oracle DB files initialize their space as soon as they are created even though they are still empty, that means the DB files initialization will preallocate space for the files created? So how 'Thin device preallocation' work with 'DB file initialization preallocation'?
For undersubscription, as thin devicies capacity is smaller than physical storage pool, what is the significance for 'thin device preallocation?