PostgreSQL, Second Edition

The libpgtcl Large-Object API

The libpgtcl library provides a number of procedures that you can use to interact with PostgreSQL large-objects. A large-object is a value that is stored indirectly. When you create a column that will contain a large-object, the column should be of type OID (object-id). When you import a large-object into your database, the bits that make up the object are stored in the pg_largeobject system table and a reference is stored in your table. Large-objects are typically used to hold images, sound files, or large pieces of unstructured data.

There are two ways to create a large-object. First, you can create a large-object using the pg_lo_creat procedure. pg_lo_creat creates a new (empty) entry in the pg_largeobject table ...