Schemas in PostgreSQL and Oracle: what is the difference?

A detailed comparison of how schemas work in PostgreSQL versus Oracle, covering key differences in user-schema relationships, namespace rules, object ownership, privileges, schema search paths, and system schemas. In Oracle, users and schemas have a strict one-to-one correspondence, while PostgreSQL treats them as orthogonal concepts. Oracle determines object ownership by schema, whereas PostgreSQL assigns ownership to the creating user. PostgreSQL uses a search_path list instead of Oracle's single default schema and synonyms. The post also highlights namespace differences that can cause naming conflicts when migrating from Oracle to PostgreSQL.