In  this  paper we  present  some of  the  results achieved  while  realizing an
international  research  project aiming  at  the design  and  development of  an
Object–Relational  Data  Warehousing  System (ORDAWA).  Important  goals  of the
project  are to  develop techniques  for the  integration and  consolidation of
different  external data  sources in  an object–relational  data warehouse,  the
construction   and   maintenance   of  materialized   relational   as   well  as
object–oriented   views,   index    structures,   query   transformations    and
optimizations, and techniques of data mining. The achievements discussed in this
paper  concern  the application  of  materialized object–oriented  views  in the
process of building an object–relational data warehouse.

Keywords:   object–relational   data   warehouse,   operational   data    store,
object–oriented  view,  view  schema,  view  materialization,  maintenance  of a
materialized view.