Default configuration keywords specific to PostgreSQL
In addition to the default DBTUNE keywords common to all DBMSs that are listed in the topic Types of configuration keywords, there is one PostgreSQL-specific configuration keyword present by default in the sde_dbtune table. It is PG_GEOMETRY.
PG_GEOMETRY contains two parameters: one to set the geometry storage to the PostGIS geometry type and one to allow the keyword to be used when creating data in ArcGIS.
The following text is how the keyword appears when exported from the sde_dbtune table:
##PG_GEOMETRY GEOMETRY_STORAGE "PG_GEOMETRY" UI_TEXT "User interface text"
This storage type provides a representation of geometry as well-known binary and well-known text. If you specify PG_GEOMETRY when you create a feature class in the geodatabase using either ArcGIS for Desktop or the ArcSDE administration command sdelayer, that particular feature class uses the PostGIS geometry storage method; the rest of the necessary parameters are picked up from the DEFAULTS keyword.
As mentioned in the topic The DEFAULTS keyword in PostgreSQL, if you specify a keyword that only has a few parameters, the rest of the parameters are read from the DEFAULTS configuration keyword. Therefore, if you specify PG_GEOMETRY when you create a feature class in a geodatabase in PostgreSQL, the software uses the values for the GEOMETRY_STORAGE parameter from the PG_GEOMETRY keyword, then goes to the DEFAULTS keyword for values for all the other parameters, such as B_STORAGE.
If you want to create a topology, terrain, or network that uses a geometry storage type other than what is stored under the DEFAULTS keyword, you need to create custom keywords that contain the desired geometry storage. For example, if you create a roads feature class using the PG_GEOMETRY keyword, when you create a network that involves that roads feature class, you want the network to also use PG_GEOMETRY. For that, you need to create a set of NETWORK composite keywords that specify PG_GEOMETRY storage.
See Composite keywords and geometry storage for details on setting up network, terrain, and topology keywords for nondefault geometry types.