Top 5 tips to improve SAP system performance

Just thinking that a wiki page discussing SAP performance in
general terms woud be helpful for the community here.

You can get involved in this blog via the following SAP wiki URL:

Let's consider the available platforms that SAP can be run on,
a few are listed here. Do feel free to add to this list and share
your own experience.

SAP on DB2 for z/OS (DB2)
SAP on Informix (INF)
SAP on DB2 UDB for i5/OS (DB4)
SAP on Windows
SAP on DB2 UDB for Unix and Windows (DB6)
SAP on Linux
SAP on SQL Server
SAP on Unix
SAP on Oracle
SAP on VMware
SAP MaxDB/liveCache

I'll start this weblog by asking you in the SAP community
network wiki to post your 'Top 5' tips you use to improve SAP system performance.

Maybe they are tips and tricks you have encountered during your many years
of experience working with SAP systems or perhaps references to installations,
upgrades or general system administration experience where a performance tip
you used and now shared could help other's in the community.

From tuning your systems memory resources such as Zero Administration Memory
Management on Windows 32-bit and 64-bit platforms to indexes that do not support predicates
that contibute to high DB request time on your system database please do share
your experiences.

So, whatever platform combination your SAP system runs on let's share your
best practices, tuning, and tips and tricks for maximizing performance.

Thanks for reading and looking forward to all your replies.