INDEXES 
Using the
system table
INDEXES, you can determine the following database information:
indices of the table ROOM and specification of which of the indices currently has the status disabled
SELECT indexname, disabled
FROM DOMAIN.INDEXES
WHERE tablename = 'ROOM'
All UNIQUE indices (regardless of which of the possible SQL statements was used to generate these indices:
CREATE INDEX statement or
UNIQUE definition)
SELECT owner, tablename, indexname
FROM DOMAIN.INDEXES
WHERE type = 'UNIQUE'

Columns of an index: see
INDEXCOLUMNS