You can have more than one spatial database in an IBM Informix instance and create a geodatabase in each database, as shown in the following graphic:
If you need to have multiple geodatabases in the same instance of Informix, set up separate databases and create a geodatabase in each database using the Enable Enterprise Geodatabase tool.
Client connections can be made to one geodatabase at a time. When connected to one geodatabase in an Informix database, you cannot query information from another geodatabase through that same connection.
For instance, you could connect to database1 in ArcGIS Desktop. When you add data to ArcMap through that connection, you cannot view the data in database2. To access the data in database2, you would set up a second database connection from ArcMap to database2.