Lesson 6

In this module you explored the basic components that make up the Oracle database software.
You saw how Oracle's software is divided into server-side components and client-side components. The meta-data stored in Oracle’s data dictionary views was described and the most commonly used views were outlined for you. You logged into the Oracle database using a simulator that imitates an actual session in SQL*Plus. You discovered that Oracle’s implementation of SQL includes all the standard SQL plus specialized extensions to SQL that run exclusively in Oracle. While it is not usually necessary to distinguish between standard and Oracle-extended SQL while working with Oracle, you learned how to adjust the SQL*Plus environment using the FLAGGER to mark queries that contain Oracle extensions. This way, if you need to create portable code, you do not have to pore over manuals to figure out what’s standard and what’s beyond the standard SQL implementation.
In this module, you learned how to:

1. Identify the primary components of an Oracle database
2. Name several data dictionary views and their purpose
3. Log into the database with SQL*Plus
4. Distinguish between standard SQL and Oracle's SQL extensions and describe when to use each

In 1983, Relational Software Incorporated was renamed Oracle Corporation to avoid confusion with a competitor named Relational Technologies Incorporated. At this time, the developers made a critical decision to create a portable version of Oracle written in C (version 3) that ran not only on Digital VAX/VMS systems, but also on Unix and other platforms. By 1985, Oracle claimed the ability to run on more than 30 platforms. Some of these platforms are historical curiosities today, but others remain in use. In addition to VMS, early operating systems supported by Oracle included

1. IBM MVS,
2. HP/UX,
3. IBM AIX, and
4. Sun's Solaris version of Unix.

Oracle was able to leverage and helped accelerate the growth in popularity of minicomputers and Unix servers in the 1980s. Today, this portability also includes releases for operating systems such as Microsoft Windows and Linux.
In addition to multiple platform support, Oracle included 1) decision support and business intelligence tools, 2) ANSI standard SQL across platforms and 3) connectivity over standard networks. Since the mid-1980s, the database deployment model has evolved from single database and application servers to client/server, Internet computing implemented using browser-based clients accessing database applications, and now to private and public cloud deployment where the Oracle Database

1. might be deployed as a service (DBaaS) or
2. used as the foundation for a Cloud Platform as a Service (PaaS).

Oracle introduced many innovative technical features to the database as computing and deployment models changed (from offering the first distributed database to supporting the first Java Virtual Machine in the core database engine to enabling grid computing and providing needed services for public and private Cloud deployment). Oracle offered support for emerging standards such as XML, important in deploying a Service-Oriented Architecture (SOA).

In this module you were introduced to the following glossary terms:

1. ODBC - Open Database Connectivity: A set of standards that define communication protocol and syntax to be used when interacting with any relational database.
2. JDBC - Java Database Connectivity: A set of standards defining a standard protocol and syntax in Java applications or applets to interact with any relational database.
3. Tablespace: Logical storage space within the Oracle database. Each tablespace is mapped to one or more physical data files. Each tablespace stores one or more tables, indexes, or other objects created within the database. A table is assigned to a single tablespace when the table is created except where you have created a partitioned table.
4. Instance: One row in an object table.
5. Schema: All the tables, views, and other objects created by a single Oracle user.
   The schema has the same name as the creating user, such as the SCOTT schema.
6. Meta-data Information: Meta-data Information is data about database structures. For example, the meta-data about a table includes its name, its column names, and the tablespace in which it resides.
7. Data dictionary views: Oracle views that display meta-data.

In the next module you will move into some new and more advanced techniques for writing queries and explore some of the Oracle extensions to standard SQL that add power to your query-writing technique.

Click the Quiz link below to take a multiple-choice quiz about SQL*Plus and Oracle's extensions to SQL.
Oracle Extensions - Quiz