What can cause performance problems in the BW system?
The causes can be both in the database and in the application. a) Causes in the database Inaccurate table statistics increase the reading load on the database because the optimizer can no longer access the tables in the most favorable way. Consequently, the data cache hit rate deteriorates. The statistics are therefore estimated using a sample rate. If this sample rate is not set correctly for large tables, this leads to inaccurate statistics being generated. For large tables, the sample rate must be set to 10%. For more information, see Note 808060. Database parameters that have been set incorrectly can also impair the performance of the BW system. This note contains detailed information on this problem. When you configure the BW database, you should pay particular attention to the disk configuration (data volumes). The size of the data cache and the correct setting of the JOIN parameters have a critical effect on the performance of a BW system. This note contains tips and references
