Your system may benefit from more appropriately placed objects if:
Single-user performance is satisfactory, but response time increases significantly when Adaptive Server executes multiple processes.
Access to a mirrored disk takes twice as long as access to an unmirrored disk.
Objects that are frequently accessed (“hot objects”) degrade the performance of queries that use the tables in which these objects are located.
Maintenance activities take a long time.
tempdb performance is affected if it shares disk space with other databases. Most system procedures and applications use tempdb as their workspace, and are adversely affected if tempdb shares the same disk with other databases.
insert performance is poor on heavily used tables.
Queries that run in parallel perform poorly, due to an imbalance of data pages on partitions or devices, or they run in serial, due to extreme imbalance.
If you experience problems due to disk contention and other problems related to object placement, check for and correct these issues:
Random-access (I/O for data and indexes) and serial-access (log I/O) processes use the same disks.
Database processes and operating system processes use the same disks.
Serial disk mirroring.
Database logging or auditing takes place on the same disk as data storage.