Using ArcCatalog

• Proxy .aux files are the main auxiliary file associated with the
UAI file. This file follows the UAI file prefix naming
convention but has an .aux suffix. Like normal .aux files, the
proxy .aux files store additional information, which is created
by ArcGIS.
• Proxy .rrd files hold the pyramid data like normal .rrd files, but
they are stored in the proxy location because of the read-only
permissions of the raster dataset or the folder. The proxy
location will never contain original raster data.
The raster proxy files are placed in a folder called rasterproxies
located in each user’s temporary directory. This location will vary
per user. If it is deemed preferable or necessary to change the
location, a registry setting is provided for this purpose.
As you cannot remove read-only raster datasets using
ArcCatalog, including raster datasets on read-only media, it is
recommended that you manually remove unnecessary proxy files
periodically, to avoid keeping unnecessary files on your harddisk.
Proxy pyramid files (.rrd) can grow substantially large.
• Display resampling—improves the way your raster dataset is
displayed
• Geodatabase rasters—multiuser access to raster datasets;
also for large raster dataset holdings (gigabytes to terabytes)
Performance tuning
There are many different formats of raster datasets that use
different mechanisms to improve access speed. ArcGIS provides
the ability to make these many formats behave in a similar manner
so the end user is required to know less about a particular format.
Since raster datasets can be large, these added abilities are
oriented toward tuning display performance. Here are some ways
to improve the performance of files:
• Creation of pyramids—improves the display speed of large
rasters
• Raster dataset compression—reduces storage space
• Calculation of statistics—for proper rendering and to be able
to perform statistical operations
WORKING WITH RASTERS 231