Using an in-memory database or a relaxed-durability database can significantly improve overall system performance.
In-memory databases run entirely in the RAPCache database memory space without using disk storage for data or logs. Because an in-memory database does not require I/O, its performance is faster than a traditional, disk-resident database. However, in-memory databases are not designed for recovery. Their transaction logs are written to the cache and not to disk, and if the database fails, data changes are lost.
Relaxed-durability extends the performance benefits of an in-memory database to disk-resident databases. Relaxed-durability databases trade the full durability of committed transactions for enhanced runtime performance for transactional workloads. See the Adaptive Server® Enterprise In-Memory Database Users Guide.