Data Archiving removes mass data, which the system no longer needs, from the database, but which must still be available for reporting. For the most part, SAP’s data archiving concept is based on the archiving objects of the Archive Development Kit (ADK).
Archiving objects describe the structure and context of the data to be archived. Predefined archiving objects are available for the applications for which data is to be archived. In data archiving, the system writes the data to archive files according to the relevant archiving objects and stores these.
Example: Financial Accounting documents are archived using the archiving object FI_DOCUMNT. This archiving object includes the document header, company code-specific postings, change documents, and related texts.
Steps for Data Archiving
Data archiving takes place in individual steps to ensure that only successfully archived data can be deleted. These are the three main steps:
- Writing the data to be archived to a new archive file
- Storing the archive files in an external store (optional)
- Deleting the archived data from the database starting from the archived files you have created
The following illustration describes the data archiving procedure.
- Familiarize yourself with the specifics of ADK-based data archiving.
- Make the settings required for Customizing for data archiving.
- Execute the data archiving.
- Use the options for viewing and analyzing archive files.
Properties of Data Archiving
As data archiving is integrated into the application, you have to be familiar with the semantics of the application data. Data archiving displays the following properties over and above saving table contents:
- Hardware independenceAs the encryption of the numeric fields, for example, the integer is dependent on the hardware, information has to be added to the archived data about the hardware used.
- Release independentAs the data structure can depend on the SAP release, information about the record layouts and field definitions is also archived.
- Dependencies between dataDependencies between data objects can be checked and taken into account for archiving.
- Company and business structureDue to the possible dependence of archived data on the organizational structure of the company, the relevant information is also archived.
Data Archiving Features
- Data security – As a result of the separation between writing the data to the archive file and deleting the data from the database, the archiving transaction can be restarted if you encounter transfer errors. You can only delete the data once it has been successfully archived. You can achieve maximum security by optionally storing the archive files in an external storage system before deleting the archived data. You can define the storage time in archiving object-specific Customizing.
- Connection to an external store – You can use the following options for storing archive files:
- Tertiary storage media, such as WORMs This can be done manually or automatically using the SAP Content Management Infrastructure (which also contains the ArchiveLink/CMS interface).
- Hierarchical storage management systems (HSM systems) in the file system. The HSM system manages the archive files automatically. For storage of the archive files, the HSM system can also use tertiary storage media.
- Data compression – During archiving, data is automatically compressed by up to a factor of 5. However, if the data to be archived is stored in cluster tables, no additional compression takes place.
- Archiving without database backup – As the data is either in the database or an archive file, you can archive data without database backup during normal system operation. However, SAP recommends that you backup archive files before storing them.
- Access to Archived Data – As the archived data has only been removed from the database and not from the application, it is available at any time. Archive Administration enables the following types of access:
- (Read) access to a single data object, such as an accounting document
- Analysis of an archive file (sequential read)
- Reloading to the database (if supported for the archiving object)
- Automatic conversion of old archive files – When archived data is read, the system automatically makes the conversions required by hardware and software changes.The Archive Development Kit (ADK) can make allowances for changes to database structures after the data was archived and for changes to hardware-dependent storage formats. The conversion does not affect the archived data. The following items are changed during automatic conversion:
- Database table schema (new and deleted columns)
- Data type of a column
- Column length
- Code page (ASCII, EBCDIC)
- Number format (such as the integer on various hardware platforms)If database structures in an application have undergone more changes than the ADK can handle (for example, if fields have been moved from one table to another or if one table has been divided into several separate tables), then a program is provided by the relevant SAP Business Suite solution for the permanent conversion of existing archive files.
- Memory space gainAs gaining an increase in memory space improves the performance of the application programs, you require information about the memory requirement of the data to be archived in the database and also the memory requirement of the archived files created.
- Call up the ABAP Dictionary ( Tools ABAP Workbench Development Dictionary).
- Enter the name of each individual table, and choose Display.