Now that many sites are migrating to DB2 V8 performance topics related to this new version are gaining popularity. Although there have been a large number of improvements made to DB2 in terms of scalability, application porting, security, and continuous availability, there are also some things you'll need to prepare your systems for.
Luckily, IBM has just updated its very useful redbook titled DB2 UDB for z/OS Version 8 Performance Topics (SG24-6465). This redbook was initially published in April 2005, but was updated with new V8 performance information and details in late February 2006. So, if you haven't picked this title up yet, now would be a good time to download and peruse it. And if you have already reviewed it, you might want to download the updated version.
The redbook gives guidance on SQL performance, subsystem performance, availability and capacity enhancements, utility performance, networking improvements, data sharing enhancements, installation and migration information, and coverage of IBM's performance tools for DB2.
If you have already migrated to V8, or are planning a migration soon, then DB2 UDB for z/OS Version 8 Performance Topics should definitely be on your reading list.