Types of Data Update with PSA 

Prerequisites

You have determined the transfer method PSA in the transfer rules maintenance.

Functions

In contrast to a data request with IDocs, a data request in the PSA also gives you various options for a further update of the data in the data targets. Upon selection, you need to weigh data security against performance for the loading process.

If you create an InfoPackage in the BW Scheduler, determine the type of data update on the Processing tab page.

PSA and Data Targets/InfoObjects in Parallel (By Package)

This method is used to update data into the PSA and the data targets with a high level of performance. The BW system receives the data from the source system, writes it to the PSA, and starts the update immediately and in parallel into the corresponding data target.

A process is started to write the data from this data packet into the PSA for each data package. If the data is successfully updated in the PSA, a second parallel process is started. In this process, the transfer rules are used for the package data records, data is adopted by the communication structure, and it is finally written to the data targets.

The maximum number of processes, which is set in the source system in customizing for extractors, does not restrict the number of processes in BW. Therefore, many dialog processes in the BW system could be necessary for the loading process. Make sure that enough dialog processes are available in the BW system.

If the data package contains incorrect data records, you have several options allowing you to continue working with the records in the request. You can specify how the system reacts to incorrect data records You can find additional information about this in the section Treating Data Records with Errors.

You also have the option of Correcting Data in the PSA and updating it from there.

PSA and Then into Data Target/InfoObject (by Package)

With a serial update of data in the PSA, and in the data targets, a process is still started for each data package that writes the data package to the PSA. When the data has been successfully updated to the PSA, the same process writes the data to the data targets afterwards.

Compared with a parallel data transfer, you have better control over the whole data flow with a serial update of data, because the BW system carries it out using only one process for each data package. Only a certain number of processes are necessary for each data request in the BW system. This number is defined in the settings made in the maintenance of the control parameters in customizing for extractors.

If the data package contains incorrect data records, you have several options allowing you to continue working with the records in the request. You can find additional information about this in the section Treating Data Records with Errors.

You have the option of correcting the data in the PSA and updating it from there.

Only PSA

Using this method, data is written to the PSA and is not updated any further.

You have the advantage of having data stored safely in BW and having the PSA, which is ideal as a persistent incoming data store for mass data as well. The setting for the maximum number of processes in the source system can also have a positive impact on the number of processes in BW.

Treating Duplicate Data Records (only possible with the processing type Only PSA):

The system indicates when master data or text DataSources transfer potential duplicate data records for a key into the BW system. The Ignore Duplicate Data Records indicator is also set by default in this case.. In BW, the last data record of a request is updated for a particular key by default when data records are transferred more than once. The remaining data records are ignored for this key in the same request. If the Ignore Duplicate Data Records indicator is not set, duplicate data records will cause an error. The error message is displayed in the monitor.

Further Updating from the PSA

Several options are available to update the data from the PSA into the data targets.

You get to the Scheduler (PSA Subsequent Update). Here you can determine the scheduling options for the background run. For data with flexible update, you can also specify and select update parameters where data needs to be updated.

When using the InfoPackage in a process chain , this setting is hidden in the scheduler. This is because the setting is represented by its own process type in process chain maintenance and is maintained there.

The monitor detail screen appears. From the Detail tab page, select one or more data packets and choose Simulate Update. In the following screen, determine the simulation selections and select Execute Simulation. Enter the data records for which you want to simulate the update and choose Continue. You see the data in the communication structure format. In the case of data with flexible updating, you can change to the view for data target data records. In the data target screen you can display, for selected records, the records belonging to the communication structure in a second window. If you have switched the debugging on, you arrive at the ABAP Debugger, and you can execute the error analysis there.

For more information, see Update Simulation in the Monitor

Processing Several PSA Requests at Once

To process several PSA requests at once, select the PSA in the PSA tree and choose Context Menu (Right Mouse Button) ® Process Several Requests. You have the option of starting the update for the selected requests immediately or using the scheduler to schedule them. The individual requests are scheduled one after the other in the scheduler. You can delete the selected requests collectively using this function. You can also call detail information, the monitor, or the content display for the corresponding data target.

During processing, a background run is started for every request. Make sure that enough background runs are available.

See also:

Tab Page: Processing