Java virtual machine

Understanding the Java Virtual Machine

Oracle's  JVM (Java  virtual  machine)  is  a  extremely  important  component  of  the  Oracle  Java strategy,  which providing  high  performance  and  scalability  although  running  Java  applications. An Oracle's JVM is tightly integrated with the database and runs on the Multi-Threaded Server. The JVM has many characteristics.

• JVM supports lightweight Java threads and shared Java byte codes.
• JVM provides a well-tuned memory manager and garbage collector which optimize the use of the SGA (40KB per user session) and the operating system's virtual memory manager.
• JVM permits Java classes to be stored in the database as database library units.
• JVM provides the NCOMP Java compiler to translate Java byte code to C executables that can be run very efficiently.
• JVM supports standard Java libraries like as Java.lang, Java.util, and Java.io.
• JVM supports JDBC driver and SQLJ translator approaches
•  JVM provides a CORBA 2.0-compliant ORB (Object Request Broker) that can be used to call in and out of the database with the CORBA/IIOP protocol.
•  JVM provides utilities to load and unload Java programs into the database.
•  JVM allows you to use Java stored procedures and triggers.
• JVM is 100% JDK 1.1.6 compliant
• JVM  allows  the  use  of  Enterprise  JavaBeans  (EJB  1.0  complaint)  through  taking  many approaches: pure java clients like CORBA/IIOP clients and D/COM clients.
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  JVM provides a standard JDBC driver, which offers the same interfaces as OCI, and thin JDBC drivers, which allow Java applications to be easily loaded into and used in the database.
• JVM efficiently uses Oracle Multi-Threaded Server (MTS). The Net8 Connection Manager also can multiplex CORBA/IIOP connections, also to Net8 connections.
• JVM provides mission-critical high availability and transparent application failover.
• JVM supports efficient load balancing on SMP and MPP architectures.
• JVM allows ease of management through the use of Oracle Enterprise Manager. OEM permits centralized monitoring and management of distributed Oracle8 servers and Java stored programs, use of standard Oracle utilities like as SQL* Loader and Export/Import for Java procedures.
• JVM allows the use of existing database security mechanisms such as roles and grants for PL/SQL, as well as Java stored procedures.
• The utilization of "invoker" rights with PL/SQL and Java stored procedures simplifies security management.
• JVM uses security features available through the advanced networking option against Java procedures.