I'm using ArcGIS 10.2.1. I have created a connection in Arc Catalog to an Oracle geodatabase. In the text box for the "instance" I put in "ddev1_linux". When I examine the connection properties, I see that it is set to "sde:oracle11g:ddev1_linux;LOCAL=gisdta". I'm curious why the LOCAL=gisdta has been appended. How do I interpret the "instance" string in the connection properties?