Introduction to Oracle Database
The most powerful tool in the world today is information. The most powerful information tool in the world is the relational database. The leading relational database in the world is Oracle Database.
What is a Database?
- Database is a collection of Objects. Objects are the building blocks inside the database. A database consists of one or more database objects.
- Database is a structured set of data held in a computer, especially one that is accessible in various ways.
- Systematically organized or structured repository of indexed information (usually as a group of linked data files) that allows easy retrieval, updating, analysis, and output of data.
- A database is an organized collection of data. It is the collection of schemas, tables, queries, reports, views, and other objects.
- A database is an organized collection of information treated as a unit. The purpose of a database is to collect, store, and retrieve related information for use by database applications.
- A database application is a software program that interacts with a database to access and manipulate data.
What is a Relational Database?
- In 1970’s paper "A Relational Model of Data for Large Shared Data Banks," E. F. Codd defined a relational model based on mathematical set theory. Today, the most widely accepted database model is the relational model.
- Computer database in which all data is stored in Relations which (to the user) are tables with rows and columns. Each table is composed of records (called Tuples) and each record is identified by a field (attribute) containing a unique value. Every table shares at least one field with another table in 'one to one,' 'one to many,' or 'many to many' relationships. These relationships allow the database user to access the data in almost an unlimited number of ways, and to combine the tables as building blocks to create complex and very large databases.
- A relational database is a database that conforms to the relational model. The relational model has the following major aspects:
- Structures - Well-defined objects store or access the data of a database.
- Operations - Clearly defined actions enable applications to manipulate the data and structures of a database.
- Integrity rules - Integrity rules govern operations on the data and structures of a database.
- A relational database stores data in a set of simple relations. A relation is a set of tuples. A tuple is an unordered set of attribute values.
- An unordered set of attribute values.
- A data structure consisting of multiple parts.
- (In a relational database) an ordered set of data constituting a record.
Oracle Database (commonly referred to as Oracle RDBMS or simply as Oracle) is an object-relational database management system produced and marketed by Oracle Corporation.
Oracle Corporation’s implementation of the Structured Query Language, or SQL, is arguably the most powerful and most significant computer language used in the world of government and business today.
What is a RDBMS?
- A relationational database management system (DBMS) is software that controls the storage, organization, and retrieval of data.
- The relational model is the basis for a relational database management system (RDBMS). An RDBMS moves data into a database, stores the data, and retrieves it so that applications can manipulate it.
- In an RDBMS, data is stored in tables, each of which consists of one or more columns of Information.
- Typically, a DBMS has the following elements:
- Kernel code - This code manages memory and storage for the DBMS.
- Repository of metadata - This repository is usually called a data dictionary.
- Query language - This language enables applications to access the data.
- An RDBMS distinguishes between the following types of operations:
- Logical operations - In this case, an application specifies what content is required. For example, an application requests an employee name or adds an employee record to a table.
- Physical operations - In this case, the RDBMS determines how things should be done and carries out the operation. For example, after an application queries a table, the database may use an index to find the requested rows, read the data into memory, and perform many other steps before returning a result to the user. The RDBMS stores and retrieves data so that physical operations are transparent to database applications.
Oracle Corporation’s implementation of the Structured Query Language, or SQL, is arguably the most powerful and most significant computer language used in the world of government and business today.
What is a SQL?
- SQL stands for Structured Query Language, or SQL(“ESS-CUE-ELL”), a language that is common to all major relational databases of all vendors worldwide.
- At its simplest level, SQL is all about—writing statements to create database objects, and then working with those objects to store and retrieve data.
- To learn more about SQL, check out "Introduction to SQL" post.
Oracle Database is an RDBMS. An RDBMS that implements object-oriented features such as user-defined types, inheritance, and polymorphism is called an object-relational database management system (ORDBMS). Oracle Database has extended the relational model to an object-relational model, making it possible to store complex business models in a relational database.
History of Oracle Database
Before the advent of the RDBMS, software developers found themselves frequently creating applications that used data. These applications needed features to store, change, and retrieve data in various forms. The data was different in every application, but the required functionality was the same—store it, change it, retrieve it. In spite of this common need for functionality, there was no common approach for getting the job done. There was no standard approach to database design, nor a standard set of logic for the storage, changing, and retrieval—each programmer recreated this logic in every application. The result was a slow development effort and proprietary data structures. Programmers found it difficult at best to share each other’s data. Even if they wanted to do it, it was often an arduous, time-consuming effort. Something better was needed.The concept of a relational database management system was first formally introduced in 1970 in a paper published by an IBM engineer named Dr. E.F. Codd. That paper was titled “A Relational Model of Data for Large Shared Data Banks”, and Codd’s work revolutionized the software industry. Codd envisioned a system within which programmers could build their own individual databases, using standard methods and functions, with built-in support for common functions to add, modify, and extract data from the database.
After Codd’s paper was published in 1970, it eventually created quite a reaction in the software industry and triggered an effort within IBM to create a commercial database product. But as IBM engineers worked on their RDBMS concept and spoke about their efforts at conferences and throughout the industry, they inadvertently inspired a young entrepreneur named Larry Ellison to create an RDBMS product of his own, one that might complement IBM’s product and, in the end, actually aligned more closely with Codd’s original theories. That competing product is known today as Oracle, and was officially released first, a few weeks before IBM’s product, which today is known as DB2. There are many commercially available RDBMS products on the market. But only one is the dominant and unquestioned leader in the field: Oracle.
Evolution of Oracle Database
The current version of Oracle Database is the result of over 35 years of innovative development.Highlights in the evolution of Oracle Database include the following:
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| Fig 1.1 Oracle Database Introduction - Oracle Database History |
- 1977 - Founding of Oracle
- In 1977, Larry Ellison, Bob Miner, and Ed Oates started the consultancy Software Development Laboratories, which became Relational Software, Inc. (RSI). In 1983, RSI became Oracle Systems Corporation and then later Oracle Corporation.
- 1979 - First commercially available RDBMS
- In 1979, RSI introduced Oracle V2 (Version 2) as the first commercially available SQL-based RDBMS, a landmark event in the history of relational databases.
- 1983 - Portable version of Oracle Database
- Oracle Version 3, released in 1983, was the first relational database to run on mainframes, minicomputers, and PCs. The database was written in C, enabling the database to be ported to multiple platforms.
- 1985 - Enhancements to concurrency control, data distribution, and scalability
- Version 4 introduced multiversion read consistency. Version 5, released in 1985, supported client/server computing and distributed database systems. Version 6 brought enhancements to disk I/O, row locking, scalability, and backup and recovery. Also, Version 6 introduced the first version of the PL/SQL language, a proprietary procedural extension to SQL.
- 1992 - PL/SQL stored program units
- Oracle7, released in 1992, introduced PL/SQL stored procedures and triggers.
- 1997 - Objects and partitioning
- Oracle8 was released in 1997 as the object-relational database, supporting many new data types. Additionally, Oracle8 supported partitioning of large tables.
- 1999 - Internet computing
- Oracle8i Database, released in 1999, provided native support for internet protocols and server-side support for Java. Oracle8i was designed for internet computing, enabling the database to be deployed in a multitier environment.
- 2001 - Oracle Real Application Clusters (Oracle RAC)
- Oracle9i Database introduced Oracle RAC in 2001, enabling multiple instances to access a single database simultaneously. Additionally, Oracle XML Database (Oracle XML DB) introduced the ability to store and query XML.
- 2003 - Grid computing
- Oracle Database 10g introduced grid computing in 2003. This release enabled organizations to virtualize computing resources by building a grid infrastructure based on low-cost commodity servers. A key goal was to make the database self-managing and self-tuning. Oracle Automatic Storage Management (Oracle ASM) helped achieve this goal by virtualizing and simplifying database storage management.
- 2007 - Manageability, diagnosability, and availability
- Oracle Database 11g, released in 2007, introduced a host of new features that enabled administrators and developers to adapt quickly to changing business requirements. The key to adaptability is simplifying the information infrastructure by consolidating information and using automation wherever possible.
- 2013 - Plugging In to the Cloud
- Oracle Database 12c, released in 2013, was designed for the Cloud, featuring a new Multitenant architecture, In-Memory column store, and support for JSON documents. Oracle Database 12c helps customers make more efficient use of their IT resources, while continuing to reduce costs and improve service levels for users.
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