In this chapter, indexes, views, functions, user-defined data types, and the rule and trigger systems have been discussed.
The view is a named query or a wrapper around a SELECT
statement. It can be used as a data access layer, provides an abstraction level, and controls data privileges and permissions.
A view in PostgreSQL can be categorized as temporary, materialized, updatable, and recursive. Simple views in PostgreSQL are automatically updatable. To make the complex views updatable, one can use the rule and trigger systems.
Indexes are physical database objects defined on a table column, a set of columns, and expressions. Indexes are often used to optimize performance or to validate data.
There are several techniques for building indexes, including B-tree, hash, GIN, GiST, and BRIN. B-tree is the default indexing method. Hash indexes are not recommended, especially in the case of streaming replication. GIN and GiST are useful for indexing complex data types and for full-text searches...