Proxy files

When a raster is used in ArcGIS, and auxiliary information (such as statistics, histograms, and pyramids) cannot be found inside the raster or in an associated auxiliary file, ArcGIS will build and store it. Normally, it is stored inside the raster itself if the format allows it, or it can be written to auxiliary files next to the raster. When a raster is marked with read-only permissions, or when the folder it is located in is marked as read-only, these auxiliary files are subsequently written to a different writable location and are known as proxy files.

What files can be contained in the proxy location?

Three types of files can be written to the proxy location:

Where is the proxy location?

The raster proxy files are placed in the RasterProxies folder located in each user's temporary directory. This location will vary per machine. If it is deemed preferable or necessary to change this location, a registry setting is provided for this purpose.

To control the location where proxy files are written, use the ArcMap Advanced Settings utility (AdvancedArcMapSettings.exe), which can be found in the Utilities folder of the ArcGIS Desktop directory. Simply start the utility, click the Raster tab, then type in your desired location for the proxy files. This key must not contain any environment variables, because they will not be expanded.

If you want to share raster proxy files with many users, consider the following:

Since you can't remove read-only rasters using ArcCatalog, including rasters on read-only media, it is recommended that you manually remove unnecessary proxy files periodically from this folder to avoid keeping unused files on your hard drive. Although the UAI and AUX files are usually small, OVR and RRD files can grow substantially large, especially when the input raster is highly compressed.

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