SAP BW Performance Optimization Book Excerpt – DB Statistics Tip

An important tasks to perform periodically on the InfoCubes is refreshing the DB statistics. This enables the query to choose the most optimal path to access and retrieve the data from the database tables. 

Alongside creating indexes for performance it is also very important that DB statistics are kept up to date. When an index is first created, DB statistics should also be recreated on the owning table using transaction code DB20 [Edit Table Statistics]. If DB statistics are not kept up to date, created indexes start to be ignored in favor of full table scans. Also, watch that the indexes do not degenerate over time. If they do, the physical size of the index will suddenly grow, sometimes to such an extent that they become larger than the table they belong to. If this happens, queries will once again start to favor full table scans. To remedy this situation the offending index will need to be dropped and rebuilt.

Keep reading…

Optimal SAP Business Warehouse reporting performance requires regular monitoring and identification of a potential performance issues. In this book, you will learn the most important processes and tools that help identify bottlenecks and solutions to solve them. Dive into the fundamental aspects of data modeling to efficient ETL (Extract, Transform, Load) This book will quickly enable SAP BW professionals to apply the techniques covered in this book to improve performance with hands-on advice and screenshots. This complete guide to SAP BW performance optimization covers:
1. Using SAP BW statistics effectively
2. Leveraging tools for extraction, loading, modeling and reporting
3. Monitoring performance using the Workload Monitor & database statistics
4. Using indexes to understand key elements of performance

Deepak Sawant and Shreekant Shiralkar are globally recognized SAP BW experts. Currently, Mr. Sawant is a Solution Arcitect in the SAP Analytics Center of Excellence at Tata Consultancy Services Ltd.. Mr Shiralkar has established, developed, and diversified businesses, both within India and globally for Fortune 500 firms and is a best-selling author.