We study the problem of maintaining materialized views of graph
structured data.  The base data consists of records containing
identifiers of other records.  The data could represent traditional
objects (with methods, attributes, and a class hierarchy), but it
could also represent a lower level data structure.  We define simple
views and materialized views for such graph structured data, analyzing
options for representing record identity and references in the view.
We develop incremental maintenance algorithms for these views.