# Query Matrix

There is no exact algorithm for memory analysis. The following table divides existing heap dump queries by the usage categories.

## Overview

Histogram | Class histogram is a list of all the objects in the heap dump. You see the number of objects, shallow and retained sizes for every class. The sorting order of the list can be changed by clicking the column header. Histogram gives you a good starting point for further analysis. Histogram can be opened by pressing the toolbar button or by activating the action link on the Overview pane.
Top Consumers | Top Consumers query returns information about the biggest objects grouped by class, class loader, and package as HTML page. The total heap is included in the analysis.

Heap Dump Overview

When a heap dump is opened the Overview editor already provides a first analysis on the heap dump:

- Check the size of the heap dump, how many object, classes, class loaders it has.
- Look at the biggest objects.

The Heap Dump Overview report can be opened via the toolbar:

Overview report contains a histogram and a top consumers overview.

- Finding Memory Leak
- Analyzing Memory Consumption