Data Archiving – a service provided by SAP NetWeaver – removes mass data that the system no longer needs online, but which must still be accessible at a later date if required, from the database. The following graphic illustrates the archiving process: Archiving objects are used to write documents to archive files, which can be stored on other media.
Data in the database can only be archived using archiving objects, which describe the data structure and context.
Financial Accounting documents are archived using the archiving object FI_DOCUMNT. It includes the document header, company code-dependent postings, change documents, SAPscript texts, and other elements.
In addition to the aforementioned technology SAP also offers XML-based archiving, as of SAP Web Application Server 6.40. With this new procedure XML archiving objects are used to write data in the form of resources either to a file system or directly to a WebDAV system, which takes on the role of the storage system shown in the figure above.
For the majority of the archiving objects the SAP Data Archiving concept is based on the Archive Development Kit (ADK). As of SAP Web AS 6.40 SAP offers an additional technology especially designed for XML-based archiving. This new technology comprises the XML Data Archiving Service (XML DAS) and the XML DAS Connector. Both ADK-based and XML-based archiving are carried out with the help of Archive Administration, transaction SARA.
For some applications it is possible to start archiving directly from the application menu. In these cases the application-specific parameters, such as the archiving object or the archiving program appear as default values.
Archiving objects for each application component are predefined in the system. Their structures are described in the application-specific sections.
The archiving procedure is divided into three main steps:
· Creation of archive files
In the write phase the data to be archived is written sequentially into newly created archive files.
· Delete from the database
The delete program reads the data from the archive files and then deletes it from the database.
· Storage of archive files
The newly created archive files can then be moved to a storage system or copied to a tape. The removal to an external storage system can be triggered manually or automatically. It is also possible to store the data before the delete phase.
In XML-based archiving this phase does not exist as a separate step. The data can be written directly to a WebDAV system.
The archiving programs are generally scheduled in the background. However, they can also run in online mode.
The following documentation describes ADK-based archiving. It is important that you understand the basic archiving concepts described in this documentation before you begin with XML-based archiving. The differences between the two technologies and processes are described under XML-based Archiving.