Take these considerations into account in order to optimize SQL performance in Cisco Unity 4.x:
Make sure the Microsoft SQL Server Desktop Engine (MSDE) Service Pack 4 (SP4) is installed. It is possible to install SP4 for SQL from the Cisco Unity System Preparation Assistant (CUSPA). CUSPA is located on Cisco Unity Service Pack CD1. This is only if SP4 is in that CD, if not you can download it from Microsoft SQL Server 2000 Service Pack 4.
Make sure the SQL recovery model is set to simple.
Shrink the database every once in a while. This should be done with every backup.
Shrink the Cisco Unity database if it grows large. Open a command (CMD) line and enter this:
osql -E use unitydb go backup log unitydb with no_log go dbcc shrinkdatabase(unitydb) go exit
Move the SQL transaction logs and database to another drive.
Refer to these documents for more information about how to move the Cisco Unity database: