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|SAP's archiving tools|
SAP, unlike most enterprise resource planning (ERP) application vendors, provides a built-in mechanism to archive data. Based on the SAP Archive Development Kit (ADK), SAP offers more than 600 archiving objects. SAP also allows third-party tools to extract business transactions from other database tables. The resulting data is written into SAP archive files containing meta data that, through SAP ArchiveLink, can be managed by a document management system.
Because SAP can handle some of the most complicated tasks of extracting business data, the method for archiving with SAP applications isn't as complicated as with some of the other ERP applications. Third-party products for SAP archiving include Open Text Corp.'s Livelink ECM (formerly IXOS), which leverages SAP's ADK to extract a complete business transaction from production tablespaces to a static file with meta data. The static file is then managed with a document management tool.
Some ERP archiving projects don't archive data into a structured dynamic tablespace, but instead archive the data into a static, file-based structure. Although the goal remains the same--to reduce the size of a production ERP database--the format of the removed content is quite different. EMC Corp.'s Documentum Archive Services for SAP, Livelink ECM from Open Text Corp. (formerly IXOS) and Princeton Softech Inc.'s Optim all extract content into unstructured static files or objects. These tools understand the business logic associated with each transaction. When the content is extracted, business-related meta data is created and associated with the file content.
The meta data enables the file to be cataloged by its business content. Livelink ECM, one of the most frequently used tools in SAP environments, leverages the SAP Archive Development Kit (ADK) to appropriately extract transactions from the SAP tablespace. Only SAP provides an API to extract transactions (see "SAP's archiving tools," this page). The output from Livelink ECM isn't another database table, but rather a file containing appropriate meta data and static content about the archived business transaction. Once created, the complementary information is removed from the production tablespace to reduce the size of the ERP production database.
Most software companies that develop dynamic archives offer the ability to create static archives. In some cases, these files have a proprietary format (Open Text's Livelink ECM, Princeton Softech's Optim) while other products use XML (HP's RIM for Databases, Solix Technologies' Archivejinni). When stored in a proprietary format, the extraction tool provides methods to review and query the extracted files. XML provides a method to describe the content independently from any specific hardware or software. Either way, the file objects contain the business meta data that makes it possible for the business to retrieve the information and understand its content.
Once the ERP content is extracted to a static file, other factors come into play to create an effective archive. The authenticity of the static data must be maintained over time and the media the data is stored on may have to meet government compliance regulations. Historically, static files were stored on optical WORM or tape, but today companies are replacing those technologies with content-addressable storage (CAS) arrays to reduce costs and provide quicker response times. In most cases, the disk arrays also support deduplication or single-instance storage to eliminate storing duplicate data. By storing the data in a disk array, it can be replicated to a secondary array in another location, which may eliminate the need to back up the archive data. Dynamic archives can be replicated as well, but because of the cost and complexity of database replication, it's generally reserved for production data only. Whatever media or storage array is used to store the extracted files, a document management system is essential to effectively manage the files and their content.
This was first published in April 2007