Exploring Memory Analysis Views > Exploring the Instances View >  Understanding the Instances View  

Understanding the Instances View

The Instances view consists of a horizontal bar chart and a table.

The Investigate By drop-down list above the chart allows you to choose which metric should be used to determine the top five categories. The options are the same as the columns in the table:

• Use Case Count

• Use Case Memory

• Heap Count

• Heap Memory

• Dead Count

• Dead Memory

 

It is important to keep in mind that the option you choose from this list affects not only the Instances view, but also subsequent views. If you cannot access a view or you do not see the data you expect to see in a subsequent view, it may be due to the Investigate by option that you chose in the Instances view.

The following table lists some examples of how to use the Investigate By options.

 

If you want to:

Choose this Investigate By option

See use case data in subsequent views

Use Case Count or Use Case Memory

See heap data in subsequent views

Heap Count or Heap Memory

See garbage data in subsequent views

Dead Count or Dead Memory

Investigate traces for dead objects

Dead Counts or Dead Memory and go to the Call Traces or Merged Allocation Points view

See instances created during your use case in the Instance Detail view

Use Case Count or Use Case Memory and go to the Instance Detail view

See all instances (inside and outside your use case)

Heap Count or Heap Memory

Some views only display certain types of data. For example, the Merged Allocation Points and Call Traces views display only use case or garbage data. You will not be able to access these views when Investigate By is set to Heap Count or Heap Memory, or when the selected class does not have any use case or garbage instances.

The bar chart in the Instances view illustrates the percentage of instances in each of the categories that are listed in the legend to the left of the chart. Hovering over a segment of the chart displays a popup showing the number of instances in or memory used by that category (see above).

You can drill down in a category by clicking either a section in the chart or the corresponding category in the legend. As you drill down to more detailed information, the chart and table refresh to show only the instances in that category. You can click the back and forward toolbar buttons to move backward and forward through operations you have already performed, or you can click the down arrow beside either button and go directly to any of the other operations that you have performed (as shown below).

Figure 1

Figure 1 Navigating the back/forward history

You can sort the table by any of the columns. The text field above the table allows you to filter the classes that are listed in the table. See Filtering Data in the Instances View for details.