Restrictions for PostgreSQL databases being used with ArcGIS

Database names must be less than 31 characters long

All identifiers (database names, schema names, table names, user names/roles, function names) must be lower case with no special characters

Ownership must be by login roles

Not all data types are supported (http://resources.arcgis.com/en/help/main/10.2/index.html#/PostgreSQL_data_types_supported_in_ArcGIS/002p0000006p000000/)