2.1.28. Creating views
- Views are partial projections
- Virtual relations, or views of live relations
- Update synchronised
- CREATE VIEW <virtual_relname>
- AS <real_relation>
- Real relation could be a query result
- Clever bit is the change propagation
- UPDATEs made to the view dataset are flooded back to relations
- INSERT and DELETE behaviour needs to be defined
- Non-trivial as INSERT into view (virtual relation) may leave holes in real relation