The purpose of this article is to introduce the concepts of Data Archiving in SAP Data Warehouse. Readers who want to get a better understanding of SAP BW Administrative Archiving in particular, and what it can do for its customers will be benefited from this article. It gives insight into the archiving processes which can be used for archiving the not much used but needed data. After reading this article you will be familiar with the benefits and potential of Administration data archiving in SAP BW.
Data Archiving Definition
Organized data constitutes information. In today’s business scenario, large amount of information is created on the fly. This information stays in the databases and systems of an organization of a long period. This information gets changes and then it gets archived and down the line it’s destroyed. This process of creation, storage, retrieval, and destruction of information is called the Information Life Cycle Management.
Data archiving focuses on effective data management and it helps in load reduction and legal compliance support. Data archiving means storing of the data into a secondary location from where it can be retrieved later whenever required.
Need for Data Archiving in SAP BW
The ever changing business environment brings in new business demands. High growth in business demand subsequently brings in a similar growth in data volume. The main challenge that a company faces today is the heavily growing SAP BW database. A huge database reduces the retrieval performance of the data at query runtime. Increase in BW database also makes the maintenance and administration efforts grow.
SAP data archiving is the only method supported by SAP to remove transaction & application data from the database in a consistent, secure and comprehensive manner. Consistency is ensured through the use of checks performed by the archiving programs. A purely database-integrated archiving is not used, because the database does not know the business context of the data to be archived. Using data archiving you can select significant objects, such as accounting documents, material master records or HR master data, and remove them from the database, without having to worry about the fundamental table design of the linked data. The archived data is stored in a file system and from there can be moved to other storage media. For security reasons the archived data is not deleted from the database until the archive files have been read and hereby confirmed.
The main advantage Data archiving offers is the reduction in resource consumption. The effect of which can be seen in the reduction of hardware costs for hard drives on the BW side where the online data will be stored, as the data grow more and more each day the need for hard drives to store the increasing data becomes unavoidable. This investment can be delayed and can be avoided for a long time, if the archiving solution is in place. The main memory and the CPU consumption will decrease; this will save the cost of administration by a large factor. Less effort for backup and disaster recovery will be required as the data gets into the archive storage at regular intervals. In systems were HANA scale out database is implemented, Data Archiving can significantly boost performance and reduce the TCO. Scope of the document is limited to administrative data archiving.
Implementing the Administrative Data Archiving in SAP BW
Existing process involves 2 steps mainly WRITE & ARCHIVE, DELETE. First step involves creating archiving session file and writing data to it. In the second step the archiving sessions are verified and the data will be deleted from DB tables. Usually archived path will not be a main memory; Later the archived data is moved to third party storage or copied to disk, etc to free critical space in production environment.
Using the archive administration Tcode SARA for the archiving object BWREQARCH, we execute an archiving program. This program writes the administration data for selected requests in an archive file. After archiving, program executes a deletion program that deletes the administration data from the database. Scheduling process explained through the below screenshots.
SARA scheduling screen, we need to select archiving object BWREQARCH, click on Write action
Create a custom variant name and click on Maintain for the variant selection screen
Variant selections in BW, requests older than 1 month will be archived, this includes DTP requests, also note minimum no of requests is set as 9999, anything above these will be archived.
Archiving sessions can be seen once the program has successfully completed
The variant selection screen can either use request date as criteria to delete or can also delete data older than XX number of months. The test mode means that the program will simulate the creation of an archive, based on your selection criteria and other archiving-object-specific checks that test the data’s archive ability, the program will not create an archive file. Choosing production mode will write program of the archiving object in production mode, it also generate statistics containing information about the table entries that were written to the archive and the size and number of archive files that were created.
But for some reason when the tool is used for first time the jobs will not be effective in reducing the size for standard SAP tables for DTP logs. Many entries are still retained in the tables RSBMONMESS_DTP, RSBMREQ_DTP, and RSBMLOGPAR_DTP.
SAP has released a correction note 2177801 to delete all the records for an archived DTP log. It is possible to only delete the logs of green requests – and you can also specify a time, “Older than XXX days”, to only delete the requests that are older than XXX days. In addition to deletion of the DTP logs the SAP correction also eliminates a dump in function module RSREQARCH_RELOAD_REQUEST_SARA.
Abap program RSREQARCH_DTP_CONDENSE_LOGS is available in the correction note to implement deletion job for deleting the old DTP log requests. Support pack 14 was a prerequisite, also some other notes need to be implemented before implementing the actual correction note 2177801.The note was applied to the BW system and the ABAP program is available to use.
In addition to scheduling RSREQARCH_WRITE program, RSREQARCH_DTP_CONDENSE_LOGS need to be scheduled in the BW production environment with a ‘Z’ variant using a process chain.
The current process of the archiving standard job through SARA has not been completely effective to reduce the SAP tables for administrative & DTP logs. Whereas the SAP delivered program in the correction note 2177801 has been effective in reducing the overall table releasing over 200 GB of free space. Regular administrative jobs should be scheduled on a daily basis in the form of process chains as described in the document to keep the system memory/DB space in check