One of the most important activities in the operation of your SAP system is managing its growth. Your business' day to day activities, like creating purchase orders and invoices, or managing your human resources, contribute to the continuous growth of your database and, to some extent, it's completely expected. Legal requirements can force you to keep these records in the system for several years, so this growth should be accounted for in your sizing.
Similarly, day to day activities also create new records in technical database tables. These can be something as trivial as logs that ABAP programs create during their execution, or IDocs - standard SAP containers for communication between systems. If not checked regularly and managed accordingly, these tables can grow to be the largest on your database, taking up several GBs of space, and can require extending your data and backup disks, which can increase your monthly hardware and operation costs. A larger database can also increase the time it can take to bring back your system online in case of an incident requiring a recovery from a backup, or even during a scheduled maintenance.
One of the tables we most frequently see SAP customers don't cleanup is BALDAT. This table, together with its header table BALHDR, contains application logs that standard transactions, and also customer developments ('Z' programs), write every time they run. Especially for programs that run on a schedule, this can quickly create thousands or even millions of entries in the database. If you haven't already, a periodic job that runs program SBAL_DELETE should be scheduled. You first have to create a proper variant - a specially defined set of parameters for this program to use when it runs - that considers for the logs you need to keep and for how long. If you also have too many historical entries, this deletion should be made carefully and in stages so as not to put too much load on your system, and to avoid filling your database's log area.
Different SAP systems also have different kinds of technical database tables that have to be checked and managed. For example, an ERP or S/4HANA system that sends emails to customers or as a result of a workflow needs to have a job to delete these sent documents, otherwise they remain on the database forever. A BW system can pile up several GBs of redundant entries in its PSA or Change Log tables. As all of this data is also backed up daily, it's important to perform these housekeeping activities to keep your database as lean as possible. If you need any assistance in determining the tables you need to cleanup, and in performing these activities on your SAP systems, please contact us to see how we can help.