DB2 Optimized for SAP – Set it and forget it

You may have read that the last release of DB2 (8.2.2) was specifically Optimized for SAP. What exactly does that mean? Well in this and the next few postings I’ll describe exactly what new features were in 8.2.2 and how, if you are using SAP (and even if you are not), you can take advantage of these new features.
The first is what I like to call the One SAP Knob.
If you administer an SAP database then you likely know that there are a number of settings SAP strongly recommends that you set. This is not a big issue when you initially get started but as new versions of DB2 and/or SAP come out it can be a burden to read through all the release notes to find out what new registry variables should be set and/or what changes to existing registry variables should be made. Well if you are on 8.2.2 your life has just gotten easier. You can turn the SAP Knob to the ON position and forget about it. What do I mean? Well there is a new registry variable in DB2 8.2.2 called DB2_WORKLOAD. If you run
db2set DB2_WORKLOAD=SAP
this will automatically set a number of registry variables based on what IBM and SAP have determined to be the optimal settings. Think of this as a parent setting which takes care of all the children registry variables underneath it. If a future fixpack of DB2 or release of SAP has new or more optimal (if that’s even correct grammar) registry settings, DB2 will automatically adjust them as long as the DB2_WORKLOAD setting is set to SAP. If you want to see what registry variables are controlled by the DB2_WORKLOAD variable, you can run
db2set -gd DB2_WORKLOAD=SAP
and you will see a list of 17 registry variables and their settings, specifically designed in cooperation with SAP to tune DB2 optimally for an SAP workload.