Best Practices for SAP BI using DB2 9 for z/OS - IBM Redbooks

5.1 Load PSA
In this section we discuss the best practices for SAP BI on DB2 9 for z/OS for
loading data into the PSA as part of the regular data loads into the SAP BI
system. We discuss techniques that can be employed to ensure that the PSA is
managed efficiently. We also discuss techniques that will optimize data loading
into the PSA as part of the data load into the SAP BI data targets.
The source systems store logically dependent data in the form of DataSources.
Using the DataSources, the data is extracted and transferred to the SAP BI
system. In an SAP BI system, the PSA is used as the input storage, which stores
the data in unchanged form. This means that if the data in the source system is
not consistent or contains errors, the data in the PSA is not error free.
The basic role of the PSA is to provide a quality check of the input data coming
from the source system. Another role of the PSA is to separate the loading
process into SAP BI from the follow-on processes like data analysis and queries.
Based on this separation, the loading performance can be tuned independently
from other SAP BI activities.
The usage of the PSA for loading into the SAP BI system is optional, but SAP
strongly recommends it from the SAP BI point of view.
For the SAP BI 7.0 Data Update, SAP BI provides the following processing
options:
► Only PSAData is just written to the PSA and is not transferred or updated to
additional data targets (for example, InfoCube, DSO).
Defining the maximum number of processes in the source system influences
the target system processes as well and improves the load performance.
► PSA and then data targets
Each data package is written to the PSA. The same process writes the data
package to the data target after the PSA is updated successfully. Updating
the data is provided serially, packet by packet.
► PSA and data targets in parallel
If the data package is successfully loaded into the PSA, a second process
writes the data into the data targets, while the other data package, if any, is
being loaded to PSA.
56 Best Practices for SAP BI using DB2 9 for z/OS