Oracle Essentials [Electronic resources] : Oracle Database 10g, 3rd Edition نسخه متنی

8.2 Oracle's OLTP Heritage

Oracle has enjoyed tremendous growth as the database of choice for
OLTP in the midrange computing
environment. Oracle6 introduced non-escalating row-level locking and
read consistency (two of the most important of
Oracle's core OLTP features), but Oracle7 was really
the enabler for Oracle's growth in OLTP.
Oracle7 introduced many key features,
including the following:

Multi-Threaded Server (MTS)

Shared SQL

Stored procedures and triggers

XA support

Distributed transactions and two-phase commits

Data replication

Oracle Parallel Server (OPS)^[1]

^[1] OPS was actually
available for DEC VMS in 1989 and for NCR Unix with the last
production release of Oracle6 (Version 6.0.36), but it became widely
available, more stable, and more popular in Oracle7.

Oracle 8.0 enhanced existing functionality and introduced additional
OLTP-related features including the following:

Connection pooling

Connection multiplexing

Data partitioning

Advanced Queuing (AQ)

Index organized tables

Internalization of the Distributed Lock Manager (DLM) for Oracle
Parallel Server

Internalization of the triggers for replicated tables and parallel
propagation of replicated transactions

Oracle8i provided the following additional
enhancements and technologies for OLTP:

Support for Java internally in the database kernel

Support for distributed component technologies: CORBA V2.0 and
Enterprise JavaBeans (EJB) v1.0

Publish/subscribe messaging based on Advanced Queuing

Cache Fusion for Oracle Parallel Server

Online index rebuild and reorganization

Database Resource Manager (DRM)

Use of a standby database for queries

Internalization of the replication packages used to apply
transactions at the remote sites

Oracle9i continued this trend, with the
introduction of Real Application Clusters, which extended the
benefits of Oracle Parallel Server to OLTP applications. Oracle
Database 10g improves the capabilities of Real
Application Clusters for deployment to a new computing model, grid
computing. But many of the capabilities that enable OLTP with Oracle
have been core to the database product for many years.

The remainder of this chapter examines many of these features in more
depth.