TeraTeam UK Teradata DBA Definition
View:
In database theory, a view consists of a stored query accessible as a virtual table composed of the result set of a query. Unlike ordinary tables (base tables) in a relational database, a view does not form part of the physical schema: it is a dynamic, virtual table computed or collated from data in the database. Changing the data in a table alters the data shown in subsequent invocations of the view.
Views can provide advantages over tables:
- Views can represent a subset of the data contained in a table
- Views can join and simplify multiple tables into a single virtual table
- Views can act as aggregated tables, where the database engine aggregates data (sum, average etc) and presents the calculated results as part of the data
- Views can hide the complexity of data; for example a view could appear as Sales2000 or Sales2001, transparently partitioning the actual underlying table
- Views take very little space to store; the database contains only the definition of a view, not a copy of all the data it presents
- Depending on the SQL engine used, views can provide extra security
- Views can limit the degree of exposure of a table or tables to the outer world
