Cache management in ArcGIS Explorer

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There are two types of caching used by ArcGIS Explorer: memory caching and disk caching.

Memory caching

Memory caching refers to assigning an amount of physical memory (RAM) for use by ArcGIS Explorer. For optimum performance you can set the amount of memory assigned for each type of data used. For example, if your 3D view contains many elevation data sources and very few 3D features, you can allocate more RAM for the elevation layers. Often an ArcGIS Explorer document that is performing poorly can become very interactive through well defined memory cache settings.

Configuring the memory cache by 3D data type

1. Click the ArcGIS Explorer Button.
2. Click ArcGIS Explorer Options.
3. Click Advanced.
4. In the Cache Management section, click 3D Memory Cache Options....
5. Enter the memory allocation values, in megabytes, for each memory type.
6. The current memory usage for each type, and the percentage of its allocated size, is detailed on the text box and horizontal graph next to each item.
7. Click OK on the ArcGIS Explorer Options dialog.

Tips

• The total memory cache size is automatically calculated as the sum of the individual settings.
• Your total memory cache size should not exceed your physical memory (RAM).
• These values will apply to all future ArcGIS Explorer sessions, so you should consider all the ArcGIS Explorer maps you will be working with when defining the memory cache settings.
• ArcGIS Explorer will not automatically balance the allocation of memory used for each data type. If you allocate a small amount of memory to a particular data type and subsequently create a document that uses that data type, it will start paging the data well before physical memory is exhausted.

Disk caching

Disk caching creates a temporary directory or cache for each layer in ArcGIS Explorer that helps you display and navigate your data efficiently. A disk cache stores the data and information that allows ArcGIS Explorer to better manage your environment by controlling levels of detail. The status of a cache is on demand. As you navigate your layers in ArcGIS Explorer, the parts of the data you zoom to are cached on demand to disk. Revisiting these areas will be faster because they are already cached. The name of a layer's disk cache is a concatenation of its display name and global unique identifer (GUID). Saving the ArcGIS Explorer document or creating a Map Content File (.nmc) will ensure that the disk cache is not inadvertently deleted, as well as retain a link to the cache for future use. When the display for a layer changes, the application automatically deletes and recalculates the layer's disk cache. You can clear the entire disk cache for an individual layer manually by clicking the dialog launcher of the Organize group on the Tools tab to display the Manage Layers dialog; then select the layer whose cache you want to delete and click the Clear Cache button.

Refresh layers

When you add content to the map that is not a globe service you'll be able to control the kind of caching to perform on the layer. The Refresh Options section of the Source Data page of the Layer Properties dialog allows you to choose how to refresh the cached data for a layer. You can choose one of three options for refreshing the cache:

• create a cache only when the layer is first opened or accessed
• create a session cache, refreshing when the map is opened or the layer is added
• refreshing the cache during the session at a specified interval

Learn more about refresh options for layers