Committed access provides a high level of data consistency because only one transaction at a time can update data blocks. Under committed access, Essbase allows transactions to hold read/write locks on all data blocks involved with the transaction until the transaction completes and commits. However, you can still allow read-only access to the last committed data values.
Essbase provides options that determine when locks are issued on data blocks:
Pre-image access (enabled by default). Pre-image access provides users read-only access to data blocks that are locked for the duration of a concurrent transaction. Users see the last committed data values for the locked data blocks.
Indefinite wait (the default). The transaction waits to acquire a lock on the required locked block.
Immediate access, or no wait. If a required block is locked by another transaction, Essbase displays a lock timeout message, and the transaction aborts.
A number of seconds that you specify. The transaction waits that number of seconds to acquire a lock on the required locked blocks. If the specified time runs out before the transaction acquires a lock, Essbase displays a lock timeout message, and the transaction aborts.
When pre-image access is enabled, you are not limited to read-only access to data blocks; if you need write access to locked blocks, the transaction waits for write access or times out, depending on the wait or timeout setting. The transaction gets immediate write access to data blocks that are not locked by another transaction.
If pre-image access is not enabled, and if you need read or write access to locked blocks, the transaction waits for write access or times out, depending on the wait or timeout setting.