Should I Load My Raster Data Into An ArcSDE Geodatabase?

Many users ask this question when dealing with raster data. Should you load raster data into an ArcSDE geodatabase? The Geodatabase Development Team has answered this question.

The pro’s of making use of an ArcSDE Geodatabase:

Fast data access
The geodatabase stores your data in blocks, which allows ArcGIS to access only the blocks of data that you need to use. Once loaded, this format allows ArcGIS to access your data very quickly.

Multi-user access
The geodatabase allows multi-user access to data whereas most file formats are not meant for multi-user operations.

Compression
Raster data can be compressed as it is being loaded into a geodatabase. Various types of compression schemes can be used including LZW, JPEG, and JPEG 2000. Note: If your file format is already compressed with a high compression factor, then the geodatabase compression may not be as highly compressed.

Better handling of NoData values
The geodatabase stores your Nodata pixels as a bit-mask rather than a value in the raster dataset. This means that you don’t need to use a pixel value as a place-holder for your NoData values like you do in most file formats.

Security (ArcSDE only)
Since your DBMS will require a user name and password, you can store your data in an ArcSDE database and know that only authorized users can access your data.

The con’s of making use of an ArcSDE Geodatabase:

Lack of third-party software support
Not all third party programs will allow an ArcGIS geodatabase to be used in conjunction with their software. This means that you are limited to the software packages that can access your data. This should be one of the considerations before you store your raster data in a geodatabase.

Lower compression than some file formats
The geodatabase allows your data to be stored with compression; however there is compression software available that can more highly compress your data – such as wavelet compression technology. For these datasets the file format may take up less storage space than the compression used by the geodatabase.

Loading Time
Since the data needs to be converted to a geodatabase block format, it takes time to load your data into the geodatabase. The larger your data, the more time it will take to load. Thankfully you only need to load your data into the geodatabase once.

This should provide some good guidelines when deciding whether to load raster data into an ArcSDE Geodatabase or not. Something to note on this:

This post only applies to the ArcSDE and file geodatabase. A personal geodatabase does not offer these same advantages.

This post can be found here: http://blogs.esri.com/dev/…