Technical Overview about 7.X Datasources. The component BW-WHM-DST-DS and transaction RSDS have been introduced with release 7.0 for the 7.X dataflow which is using the transformation and datatranfer process.
Datasources contains a set of fields that provide the data for a business unit for data transfer into BW. From a technical point of view, the Datasource is a set of logically-releated fields that are provided to transfer data into BW in a flat structure.
SAP Online Documentation
Useful transaction and tables:
|RSDS||view of the datasource; 7.X datasources can be changed within this transaction, 3.X datasources are only displayed|
|RSDS||active and modified version of a datasource|
|RSDSSEG||DataSource - Segments which also includes PSA name|
|RSDSSEGFD||DataSource - Segment Fields|
|RSTSODS||field USEROBJ includes the datasource and the sourcesystem; PSA table is available|
|RSTSODSFIELD||fields of the PSA table|
|RSDS_DATASOURCE_ACTIVATE_ALL||re-activation of 7.X datasources where already an A version exists|
|RSDS_DDIS||metadata of datasource in BW system|
|( RSOAS_DDIS||metadata of datasource for 3.X datasources)|
This report is used to cross check the field USEROBJ in RSTSODS with the fields(DATASOURCE , LOGSYS) of RSDSSEG.
This report is used to find the psa's which are not mapped to any NEW_DS (entry in RSTSODS, no entry in RSDSSEG)
Transport of datasources
As the datasources are sourcessystem dependent the system will create a T version during the import of the datasource. In the After-Import-Methode RS_RSDS_AFTER_IMPORT the datasource determine the new sourcesystem according to table RSLOGSYSMAP an activate the datasource.After an successful activation the T version will be deleted during the transports.Before transporting the datasource in BW make sure that the datasource is available or has been transported to the transport sourcesystem of your BW system.
Transport/TLOGO object in BW is RSDS
Transport/TLOGO object in BW is OSOA
possible for the following source systems:
- SAP system
- Myself connection or other BW system
Replicating a datasource from a source system the first time will not automatically activate the datasource. The metadata are stored in table RSDS only in M version. During the activation of a datasource the system generates the DDIC objects and the transfer structure in BW and in the sourcesystem, and the PSA table. To avoid a creation of necessary objects it is necessary to activate needed datasources in the development manually and trasnport them to the productive system. (SAP note 925228)
When a DataSource is replicated the first time, it has to be decided which object type (ISFS vs. RSDS) has to be chosen.
--> A DataSource (in one specific logsys) in the BW system can either exist as 3.x DataSource or 7.x DataSource – both objects at the same time are NOT allowed!
--> At replication time a decision for one object type has to be taken for unknown datasources in BW. Unknown means that the datasource has not been replicated yet or not content (D version) exists (SHMP vs. SHDS)
Reasons why replication does not work:
- check RFC connection in transaction sm59 for the appropriate sourcesystem and make sure that the correct RFC connection will be used according to table RSLOGSYSDEST
Option internal and external format
In the definition of the datasource you can select whether the data from the source system are available in internal or external format. In case of a SAP source system the data are available in internal format and the Conversion Routine of the source System is visible in column 'SS.Conv.Rout.
What has to be considered concerning internal and external value
Definition of internal and external value.
Internal: how the data are stored on the database
External: how the data are displayed
Upload from SAP source system
In general the values are already available in internal format and therefore no conversion is necessary. Which conversion is used is visible in the field 'SS.Conv.Rout.' If the datasource field is assigned to an infoobject which use the same conversion exit, no conversion is necessary. Exception the definition is different in the source and BW system. e.g. transaction OSML for converison MATN1.
Upload from external source systems
If the data are not available in internal format you have two possiblities:
- in the definition of the datasource by selecting "external' for the column 'format'. In that case the system will already convert the data into internal format before writting into PSA
- define a routine in the transformation which is calling the function module 'CONVERSION_EXIT_*****_INPUT'
******** --> name of the conversion exit of the appropriate infoobject
|procedure||internal view||external view|
|preview in the transaction RSDS||X|
|PSA manage screen||X|
|detail view in transaction se16||X|
call PSA table via transaction se16
call PSA table via transaction se16
If the flag 'Transfer' is not set the fields will not be available in the subsequent objects like the transformation for example. If you need the field, make sure that the option 'transfer' is set.
Changing the datasource
If you change a datasource in the sourcesystem and replicate the changes into BW system or perform changes directly in RSDS a new version of the PSA table can be created. It depends wether the old version of the datasource contains data or not. In case there are no data available in the PSA table no new version will be created. If there a data available and the structure or datatype has been changed in a way that is not compatible with the database (abbreviated or type changed, for NUMC also made longer) or a field has been deleted, a new PSA version will be created with the new format. The old data remains in the old PSA table but ca no longer be extracted using standard methods. Therefore make sure that there is no data remaining in the PSA table of the datasource that has not yet been uploaded to the infoprovider.
examples with data records in the PSA table
|old||new||new PSA version|
|CHAR (5)||CHAR (10)||no|
|CHAR (5)||CHAR (3)||yes|
|adding a field||no|
|remove a field||yes|