The functions of Buffer Pool Analyzer
This topic introduces the suite of Buffer Pool Analyzer tools that are available for z/OS®, respectively the equivalent tools of DB2® Performance Expert for z/OS. This topic is relevant only for users of the Buffer Pool Analyzer stand-alone product or Db2 Performance Expert for z/OS.
- Before Buffer Pool Analyzer can provide any useful information about buffer pool activities and its performance, it needs to collect data from a Db2 subsystem. Buffer Pool Analyzer lets you collect buffer pool related Db2 trace data on the host and makes this data available in data sets on the host. Buffer Pool Analyzer uses this trace data for performance reports, object placement optimization, and simulation tasks.
- Buffer Pool Analyzer can create activity reports at different levels from collected trace data. Reports are provided in textual form in data sets on the host. You can use them to review the buffer pool performance or to perform an in-depth analysis of the buffer pool behavior.
- Buffer Pool Analyzer can create aggregated buffer pool data files, referred to as bpd files, from collected trace data. These bpd files contain data in a format that is suitable for most client-based functions of Buffer Pool Analyzer. The contents of bpd files can also be loaded into Db2 tables.
- In addition to the host-based text reports, you can view performance data on a client in graphical form. This function shows buffer pool comparison data and individual buffer pool information.
- Buffer Pool Analyzer can optimize the object placement in buffer pools. It analyzes bpd file data on the client and generates recommendations for the assignment of objects to buffer pools and for initial buffer pool sizes and parameters. This function provides a wizard that guides you through the optimization. You can manipulate the predefined expert rules and the parameters of an optimization. The function generates appropriate Db2 ALTER BUFFERPOOL commands and SQL ALTER statements. You can use these results to tune a system directly.
- Buffer Pool Analyzer can perform a simulation of the effects of different object placements and buffer pool sizes. It uses representative trace data on a client, lets you vary the parameters, and predicts the effectiveness of buffer pools in terms of hit ratios. You can use this function to assess the effects of planned changes before you actually apply them to a system.
The following topics provide the basic knowledge about each function and should enable you to perform the how-to instructions that are described in the remaining topics.