&reftitle.intro; PostgreSQL database is an open source product and available without cost. Postgres, developed originally in the UC Berkeley Computer Science Department, pioneered many of the object-relational concepts now becoming available in some commercial databases. It provides SQL92/SQL99 language support, transactions, referential integrity, stored procedures and type extensibility. PostgreSQL is an open source descendant of this original Berkeley code. &reference.pgsql.setup; &reference.pgsql.constants; &reference.pgsql.examples; &reference.pgsql.reference; &reference.pgsql.pgsql.connection; &reference.pgsql.pgsql.result; &reference.pgsql.pgsql.lob;