The SYSCOLLATIONMAPPINGS compatibility view contains only one row with the database collation mapping. It is obtainable via built-in functions and is not kept in the catalog. Following is definition for this view:
ALTER VIEW "SYS"."SYSCOLLATIONMAPPINGS" as select DB_PROPERTY('Collation') as collation_label, DB_EXTENDED_PROPERTY('Collation','Description') as collation_name, DB_PROPERTY('Charset') as cs_label, DB_EXTENDED_PROPERTY('Collation','ASESensitiveSortOrder') as so_case_label, DB_EXTENDED_PROPERTY('Collation','ASEInsensitiveSortOrder') as so_caseless_label, DB_EXTENDED_PROPERTY('Charset','java') as jdk_label