Connecting to an ArcSDE Database

Connecting to an ArcSDE database is the same for the reader and the writer. They both use the same directives in the same manner.

There are two possible ways to connect to an ArcSDE database:

  • connecting to the ArcSDE service, which in turn communicates with the underlying database (a three-tier architecture), and
  • connecting to the underlying database directly (a two-tier architecture).

With a direct connection (the two-tier architecture), you will still need to install the SDE Software Development Kit. This should be installed into the bin folder of a folder that can be pointed to by the SDEHOME environment variable.

As of ArcGIS 10.1, the two-tier architecture has become the default method of connecting.