The Data Size view is available for experiments that contain data that has a size element such as a number of bytes. Experiments that include heap tracing, I/O tracing, or MPI tracing have a Data Size view.
The Data Size view organizes the data into ranges of data sizes and calculates the metrics for the events whose data falls into a given range. Data without a size element is attributed to data size 0.
You can use the Data Size view to filter the data. For example, in an experiment that contains heap tracing data, you could select a size range line that has high metrics for Bytes Leaked and add the filter Include only events with selected items. When you go to other data views, the data is filtered to show only events that produced memory leaks of that size range you selected.