PG_NAMESPACE Sistem Tablosu - Data Catalog

Giriş
Schema bilgisini saklar. Açıklaması şöyle

"One key difference between PostgreSQL and standard relational database systems is that PostgreSQL stores much more information in its catalogs: not only information about tables and columns, but also information about data types, functions, access methods, and so on," states the developer of Postgres. Users can modify these tables, which means Postgres can be extended by a user, unlike with most conventional database systems, which require hardcoded changes in the source code to modify the software.

Örnek
Şöyle yaparız

SELECT quote_ident(nspname) FROM pg_namespace WHERE nspname LIKE '%5%';