About View Storage in Greenplum Database

• A view has no data files (because it holds no data).

• The value of for a view is v rather than r.

For more technical information about views, see the PostgreSQL documentation about Views and the Rule System.

• Object names are resolved during , so the current setting of search_path affects the view definition.
• Objects are referred to by their internal immutable object ID rather than by their name. Consequently, renaming an object or column referenced in a view definition can be performed without dropping the view.
• Greenplum Database can determine exactly which objects are used in the view definition, so it can add dependencies on them.

Note that the way Greenplum Database handles views is quite different from the way Greenplum Database handles functions: function bodies are stored as strings and are not parsed when they are created. Consequently, Greenplum Database does not know on which objects a given function depends.

These system catalog tables contain the information used to determine the tables on which a view depends.

• pg_depend - object dependency information for database-specific (non-shared) objects.
• - rewrite rules for tables and views.
• pg_attribute - information about table columns.