Databases Reference
In-Depth Information
ditional functionality using PL/SQL programs included with the database, referred to
as packages, which can be called from standard PL/SQL code.
Java
Oracle8
i
introduced the use of Java as a procedural language and a Java Virtual Machine
(JVM) in the database (originally called JServer). The JVM includes support for Java
stored procedures, methods, triggers, Enterprise Java Beans (EJBs), CORBA, IIOP, and
HTTP.
The inclusion of Java within the Oracle Database allows Java developers to leverage their
skills as Oracle applications developers. Java applications can be deployed in the client,
Application Server, or database, depending on what is most appropriate. Current Oracle
Database versions include a just-in-time Java compiler that is enabled by default. The
importance of Java to Oracle is illustrated by the acquisition of Sun by Oracle in 2010
and continued development efforts around Java since.
Oracle and Web Services
As of Oracle Database 11
g
, the Database can serve as a Web Services provider imple‐
mented through XML DB in the database. Web services enable SQL or XQuery to submit
queries and receive results as XML, or invoke PL/SQL functions or package functions
and to receive results. XQuery provides support for the JSR standard and is further
optimized for performance in the Oracle Database. As of Oracle Database 12
c
, XQuery
updates are supported. You can also define RESTful Web Services to access both SQL
and PL/SQL in an Oracle Database through the APEX Listener, described in
Chapter 15
.
Large objects
The Oracle Database has been able to store large objects since Oracle8 added the capa‐
bility to store multiple LOB columns in each table. Oracle Database 10
g
essentially
removed the space limitation on large objects. Oracle Database 11
g
greatly improved
the performance of query and insert operations when used with LOBs through the
introduction of SecureFiles. SecureFiles serve as a place to securely store LOBs in the
Oracle Database instead of in filesystems while delivering performance similar to that
experienced when LOBs are stored in filesystems. Transparent Data Encryption, a se‐
curity feature described below and later in the topic, is supported for SecureFiles LOB
data.
Object-oriented programming
Support of object structures has existed since Oracle8
i
to provide support for an object-
oriented approach to programming. For example, programmers can create user-defined
data types, complete with their own methods and attributes. Oracle's object support
includes a feature called Object Views through which object-oriented programs can
make use of relational data already stored in the database. You can also store objects in
the database as varying arrays (VARRAYs), nested tables, or index-organized tables
(IOTs).
