ArcSDE is a high-performance, object-based spatial data access engine. It is implemented in several commercial relational database management systems using open standards and true client/server architecture. ArcSDE makes it possible to store a large number of features in a continuous database. ArcIMS supports ArcSDE raster and vector data.

For raster data, ArcIMS supports the following:

• Pixel depths: All pixel depths (1 - 64) are supported.
• Transparency bitmasks: If the raster data was loaded into ArcSDE with a transparency bitmask, ArcIMS will automatically read it.
• Colortables: If a colortable is available for the raster data, ArcIMS will take advantage of it.
• Statistics: If statistics have been generated for the raster data, ArcIMS will take advantage of them. If they have not been generated, ArcIMS will not generate the statistics, and the raster data may draw with unexpected results.

For information on the versions of ArcSDE supported by ArcIMS, see the ArcIMS System Requirements on the ESRI support site.

Using direct connect

You can access ArcSDE using direct connect. You must install the client on each of your Spatial Server machines. For more information on the installation, refer to the Appendix titled 'Making a Direct Connection' in the ArcSDE Configuration and Tuning Guide for your RDBMS.

Before you install the client, you need to be aware of the following steps specific to ArcIMS:

• You must add SDEHOME to your list of environment variables. The value should refer to the ArcIMS server directory: <ArcIMS Installation Directory>/server. In the PATH enfironment variable, add %SDEHOME%/bin.
• You must restart ArcIMS Monitor and ArcIMS Application Server.

ArcSDE connection variables

In order to connect to ArcSDE, you must enter a series of connection variables. The following tables summarize typical values for supported databases.

Database	Instance	Database	Password
Oracle with ArcSDE	Port:5151 (Note 2)	Optional	MyPassword
Oracle with direct connect	sde:<client> sde:oracle9i (Oracle 9i) sde:oracle10g (Oracle 10g)	Optional	MyPassword @netservicename
SQL Server with ArcSDE	Port:5151 (Note 2)	Database name	MyPassword
SQL Server with direct connect	sde:sqlserver:<sql server instance name>	Database name	MyPassword
SQL Express for Workgroups with direct connect	sde:sqlserver:<machine name>\<sql server instance name>	Database name	MyPassword (Note 1)
DB2	Port:5151 (Note 2)	Optional	MyPassword
DB2 with direct connect	sde:db2	DB alias name	MyPassword
Informix	Port:5151 (Note 2)	Optional	MyPassword
Informix with direct connect	sde:Informix	ODBC datasource name	MyPassword

Note 1: To use SQL Express for Workgroups with direct connect, you must use Windows authentication for the username and password. The username must include the domain, for example, "mydomain\myuseraccount". The same user account that is used for running the ArcIMS Monitor service should be used as the username and password for SDEWORKSPACE. In addition, the user account must have read access to the database at a minimum.

Note 2: If you are using a different port number than 5151 for ArcSDE, you should use that port number instead for the instance.

ArcSDE for Coverages

Coverages store geographic features and their data in a topological vector format that allows for complex geoprocessing and sophisticated spatial analysis. The primary feature types for coverages are nodes, arcs, and polygons. ArcSDE for Coverages is used to access ArcInfo coverages in ArcIMS. Connection variables for ArcSDE for Coverages are the same as for ArcSDE (without direct connect).

Adding an ArcSDE connection