Oracle C++ Call Interface Programmer's Guide

Object Support
Multiple applications running against the same server will each have their own
object cache. The client-side object cache tracks the objects that are currently in
memory, maintains references to objects, manages automatic object swapping and
tracks the meta-attributes or type information about objects. The client-side object
cache provides the following benefits:
■ Improved application performance by reducing the number of client/server
round-trips required to fetch and operate on objects
■ Enhanced scalability by supporting object swapping from the client-side cache
■ Improved concurrency by supporting object-level locking
Runtime Environment for Objects
OCCI provides a runtime environment for objects that offers a set of methods for
managing how Oracle objects are used on the client side. These methods provide
the necessary functionality for performing these tasks:
■ Connecting to an Oracle database server in order to access its object
functionality
■ Allocating the client-side object cache and tuning its parameters
■ Retrieving error and warning messages
■ Controlling transactions that access objects in the database
■ Associatively accessing objects through SQL
■ Describing a PL/SQL procedure or function whose parameters or result are of
Oracle object type system types
Associative and Navigational Interfaces
Applications that use OCCI can access objects in the database through several types
of interfaces:
■ SQL SELECT, INSERT, and UPDATE statements
■ C++ pointers and references to access objects in the client-side object cache by
traversing the corresponding references
OCCI provides a set of methods to support object manipulation by using SQL
SELECT, INSERT, and UPDATE statements. To access Oracle objects, these SQL
statements use a consistent set of steps as if they were accessing relational tables.
OCCI provides methods to access objects by using SQL statements for:
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