Chapter 9. PostgreSQL Extensions to the JDBC API

Table of Contents

• Accessing the Extensions
• Geometric Data Types
• Large Objects
• Listen / Notify
• Server Prepared Statements
• Physical and Logical replication API

PostgreSQL is an extensible database system. You can add your own functions to the server, which can then be called from queries, or even add your own data types. As these are facilities unique to PostgreSQL , we support them from Java, with a set of extension APIs. Some features within the core of the standard driver actually use these extensions to implement Large Objects, etc.

Accessing the Extensions

To access some of the extensions, you need to use some extra methods in the org.postgresql.PGConnection class. In this case, you would need to case the return value of Driver.getConnection() . For example:

Connection db = Driver.getConnection(url, username, password);
// ...
// later on
Fastpath fp = db.unwrap(org.postgresql.PGConnection.class).getFastpathAPI();