Highlights the icons that have a significant number of rows.
You can choose to highlight expensive icons in the query graph. You can also choose not to. The highest cost icons are based on the number of rows that were processed for that operation. The cost is considered "high" relative to the other icons in the graph (the absolute value of the row can be low).
To highlight expensive icons:
Note that these options depend on the type of Visual Explain diagram you selected.
To remove the highlighting: