Oracle Overview of Oracle feature 1, Architecture of Oracle database, and common commands

1. Oracle Overview

-Oracle Database, referred to as Oracle. Oracle (Oracle) is an object-relational database management system (ORDBMS) in the United States. Currently occupies a major share of the database market.

-Oracle's history: 1977 Ellison and two friends, established RSI company; in the summer of 1979, RSI released Oracle Second edition, 1983, release Oracle Third Edition, and renamed Oracle Company in 1983 (meaning "The source of all wisdom") 1986, became the fourth largest software company in the World, June 1992, Oracle released the 7th edition; In 1997, Oracle released the 8th edition; in June 2001, Oracle released Oracle 9I;2003 September, Oracle released Oracle 10g; Oracle 11g was released on July 11, 2007, and Oracle 12c was released in 2013. (Note: This series of topics uses Oracle 11g. ）

-Why Learn Oracle?

-Excellent performance, model in large database, object-relational database management system (ORDBMS), widely used in management information, enterprise data processing, Internet, e-commerce and other fields.

-Superior performance in data security and data integrity control, cross-operating systems, data interoperability across hardware platforms, support for multi-user, transaction handling of event volumes, and portability.

-Oracle 11g Installation tutorials are not detailed, see https://jingyan.baidu.com/article/363872eccfb9266e4aa16f5d.html Web page

-Oracle 11g Uninstall: First find the directory App\administrator\product\11.2.0\dbhome_1\deinstall, Click Deinstall.bat (a command-line window opens), and then follow the command-line prompts step-by-step.

2. Oracle Database Architecture

-Oracle or Oracle database refers to Oracle database management system as it is commonly referred to. It consists of two parts: Oracle database and Oracle instance.

-Oracles Database: A collection of related operating system files (that is, files stored on your computer's hard disk) that are organized together to become a logical whole, that is, an Oracle database.

-a database is a collection of data that is used by Oracle to store and manage relevant information.

-The Oracle database must work with an in-memory instance to provide data management services externally.

-Oracle instance: A data structure located in physical memory that consists of multiple background processes and a shared pool of memory for the operating system, and the shared memory pool can be accessed by all processes.

-Oracle Instance = Memory used by process + process [SGA (System Global area)].

Oracle Overview of Oracle feature 1, Architecture of Oracle database, and common commands