Reducing Data

As mentioned earlier, all real-time data that are collected from the profiled process are stored in a history. Since storing data for an extended period of time will use increasing amounts of memory, the stored data have to be reduced. There are two limits determining the amount of memory used for the real-time data history:

1. Maximum memory used by global memory statistics and types and resources that are included in the graph.

2. Maximum memory used by types and resources that are not included in the graph.

When a limit is reached, data are removed from the beginning of the affected histories until the memory used is below the limit again.

Having two limits allows data to be collected for all types and resources, not just types and resources that are included in the graph. If all types and resources were to be collected and only one limit were used, the amount of memory used by types and resource not included in the graph (presumably not very important data) would overwhelm the amount of memory used by global statistics and included types and resources. There may be thousands of types in the profiled process, but probably only a few of them are included in the graph. On the other hand, not collecting data from types and resources not included in the graph would lead to missing data before you get a chance to include the item in the graph.

The default limits for data reduction are:

1. 1,024 Kbytes for memory used by global memory statistics and types and resources with collection of historical real-time data.

2. 2,048 Kbytes for memory used by types and resources that are not collected.

These limits can be changed using the Tools->Options form, or the session or project property pages.