From Xojo Documentation
Creates a PostgreSQLLargeObject and returns its ID. Legal IDs are positive integers. Therefore, if CreateLargeObject returns 0 or less, then there was an error creating the large object. Use ErrorMessage to determine what the error was.
PostgreSQL requires that all large object operations be performed inside of a transaction. Therefore, you must start a transaction before you perform your first large object operation:
After you have performed your last large object operation, you should close the transaction, like this:
Please see the PostgreSQLLargeObject class for information on how to work with large objects.
Create a large object: