A view is a stored query that encapsulates one or more SELECT statements. Views dynamically access and compute data from the database at execution time. A view is read-only, and can reference any combination of tables, temporary tables, and other views.

You can use views to achieve the following goals:

  • Hide the complexity of SELECT statements from users for support or security purposes. For example, you can create a view that exposes only the data users need from various tables, while withholding sensitive data from the same tables.
  • Encapsulate details about table structures, which might change over time, behind a consistent user interface.

Unlike projections, views are not materialized—that is, they do not store data on disk. Thus, the following restrictions apply:

  • Vertica does not need to refresh view data when the underlying table data changes. However, a view does incur overhead to access and compute data.
  • Views do not support inserts, deletes, or updates.

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