SAP ASE database recovery includes checking buffer pool sizes and setting async prefetch.
Log I/O size – SAP ASE uses the largest buffer pool available in the default data cache for log I/O. If a pool with the largest buffer size is unavailable, the server dynamically creates this pool, and uses the pool for log I/O. The buffers for this pool come from the default pool. Recovery tunes the size of the large buffer pool for optimal recovery performance. If the large pool is available but its size is not optimal, SAP ASE dynamically resizes it, and the default pool, for optimal recovery performance. The buffer pool configurations are restored at the end of recovery.
See Performance and Tuning Series: Basics > Memory Use and Performance.
async prefetch limit – during recovery, the server automatically sets the local async prefetch limit for the pools in the default data cache used by recovery to an optimal value. This overrides any user specifications for the duration of recovery.
When recovery completes, the original configuration values are restored.