introduction to oracle database

Oracle Database

Introductionof

By

Puja Dhar

ORACLE HISTORY

Larry Ellison and his two friends and former co-workers, Bob Miner and Ed Oates, started a consultancy called Software Development Laboratories (SDL) in 1977. SDL developed the original version of the Oracle software.

Developer

UsageOracle Database Architecture. An Oracle database is a collection of

data treated as a unit. The purpose of a database is to store and retrieve related information. A database server is the key to solving the problems of information management.

The i in oracle 8i and 9i stands for INTERNET and the g in 10g and 11g stands for GRID, because from 10g onwards oracle supports grid architecture.

Meaning of i & g in Oracle databases

Oracle released Oracle Database 12c into general availability July 1, 2013. According to Oracle, this is "the first database designed for the cloud.”

Meaning of Oracle 12c

ORACLE HISTORY 1979 Oracle Release 2 1986 client/server relational database 1989 Oracle 6 1997 Oracle 8 (object relational) 1999 Oracle 8i (Java Virtual Machine) 2000 Oracle Application Server 2001 Oracle 9i database server

The major Oracle versions, with their latest patch-sets are: Oracle 7: ... - 7.3.4.5Oracle 8: 8.0.3 - 8.0.6 Oracle 8i: 8.1.5.0 - 8.1.7.4 Oracle 9i (Release 1): 9.0.1.0 - 9.0.1.4 Oracle 9i (Release 2): 9.2.0.1 - 9.2.0.8Oracle 10g (Release 1): 10.1.0.2 - 10.1.0.5Oracle 10g (Release 2): 10.2.0.1 - 10.2.0.5Oracle 11g (Release 1): 11.1.0.6 - 11.1.0.7Oracle 11g (Release 2): 11.2.0.1 - 11.2.0.4Oracle 12c (Release 1): 12.1.0.1 - 12.1.0.2.0

Note: If running on one of the above releases, it is recommended to always install the latest patch-set.

OVERVIEW OF ORACLE GRID ARCHITECTUREGrid computing is a new IT architecture that produces more resilient and lower cost enterprise information systems. With grid computing, groups of independent, modular hardware and software components can be connected and rejoined on demand to meet the changing needs of businesses.Benefits of Grid Computing Compared to other models of computing, IT systems designed and implemented in the grid style deliverhigher quality of service, lower cost, and greater flexibility. Higher quality of service results from having no single point of failure, a robust security infrastructure, and centralized, policy-driven management. Lower costs derive from increasing the utilization of resources and dramatically reducing management and maintenance costs. Rather than dedicating a stack of software and hardware to a specific task, all resources are pooled and allocated on demand, thus eliminating under utilized capacity and redundant capabilities. Grid computing also enables the use of smaller individual hardware components, thus reducing the cost of each individual component and providing more flexibility to devote resources in accordance with changing needs.

ORACLE FAMILY Personal Oracle- for single users. Used to

develop systems Oracle Standard Edition- (Entry level

Workgroup server) Oracle Enterprise edition- Extended

functionality Oracle Lite- (Oracle mobile) single users using

wireless devices.

SOME DEVELOPER TOOLS Oracle Forms Developer Oracle Reports Developer Oracle Jdeveloper Oracle Designer

FILE PROCESSING

DatabaseProcessing

DATABASE STRUCTURE

Logical structure - maps the data to the Physical structure.

Physical structure -part of the operating system’s file structure.

Memory structure - where all the processing takes place.

THE LOGICAL STRUCTURES control how the data must be stored in

the database. five Logical structures:

tablespaces segments extents data blocksschema objects

PHYSICAL STRUCTURES Parameter files Password files Datafiles Redo log files Control files

TABLESPACES A database is divided into logical

storage units called Tablespaces. logical construct for arranging different

types of data An Oracle database must have at least a

system tablespace. It is recommended to have different

tablespaces for user and system data.

SCHEMAS AND SCHEMA OBJECTS Collection of database objects

TablesViewsSequences IndexesProceduresFunctionsPackagesTriggers

DATA BLOCKS The smallest unit of Input/Output used by

Oracle database. The size of data block for any database is fixed

at the time of creation of the database; Some values of the data block size are 2KB,

8KB, 16KB, and 32KB. Oracle recommends a size of 8KB

EXTENTS The next level of data storage. One extent consists of a specific number

of data blocks One or more extents in turn make up a

segment. When the existing space in a segment is

completely used, Oracle allocates a new extent for the segment.

SEGMENT A segment consists of a set of extents Each table’s data is stored in its own

single segment. Each index’s data is stored in a single

segment. More extents are automatically allocated

by Oracle to a segment if its existing extents become full.

The different types of segments are the data segments, index segments,rollback segments, and temporary segments.

PHYSICAL DATABASE STRUCTURE Password file - which contain the password

information for all users. Parameter file - which contains all the

important information necessary to start a database.

Datafiles - which contain the application data being stored, as well as any data necessary to store user-IDs, passwords, and privileges.

Redo log files - which store all the transactions made to the database. These files are also called transaction log files.

Control files - which store information specifying the structure of the database,such as the name and time of creation of the database and the name and location of the datafiles.

SECURITY MECHANISMS Database users and schemas Privileges Roles Storage settings and quotas Resource limits Auditing

DATA ACCESS: SQL Data definition language (DDL)

statements Data manipulation language (DML)

statements Transaction control statements Session control statements System control statements Embedded SQL statements

TRANSACTIONS A transaction is a logical unit of work that

comprises one or more SQL statement executed by a single user. According to the ANSI/ISO SQL standard, with which Oracle is compatible, a transaction begins with the user’s first executable SQL statement. A transaction ends when it is explicitly committed or rolled back.

TRANSACTION EXAMPLE

DATA ACCESS: SQLSession Control StatementsThese statements let a user control the properties of the current session, including enabling and disabling roles and changing language settings. The two session control statements are

ALTER SESSION and SET ROLE.

System Control StatementsThese statements change the properties of the Oracle database instance. The only system control statement is ALTER SYSTEM.

It lets users change settings, such as the minimum number of shared servers, kill a session, and perform other tasks.

Embedded SQL StatementsThese statements incorporate DDL, DML, and transaction control statements in a procedural language program, such as those used with the Oracle precompilers. Examples include OPEN,

CLOSE, FETCH, and EXECUTE

Overview of Data typesEach column value and constant in a SQL statement has a data type, which is associated with a specific storage format, constraints, and a valid range of values. When you create a table, you must specify a datatype for each of its columns.Oracle provides the following built-in data types:Character datatypesNumeric datatypesDATE datatypeLOB datatypesRAW and LONG RAW datatypes

Relational Model Concepts A Relation is a mathematical concept based

on the ideas of sets

The model was first proposed by Dr. E.F. Codd of IBM Research in 1970 in the following paper:– "A Relational Model for Large Shared Data Banks,"

Communications of the ACM (Association for Computing machinery), June 1970

The above paper caused a major revolution in the field of database management

FUNCTIONS OF A DBMS Data definition: SQL lets a user define the structure and

organization of the stored data and relationships among the stored data items.

Data retrieval: SQL allows a user or an application program to retrieve stored data from the database and use it.

Data manipulation: SQL allows a user or an application program to update the database by adding new data, removing old data, and modifying previously stored data.

Access control: SQL can be used to restrict a user’s ability to retrieve, add, and modify data, protecting stored data against unauthorized access.

Data sharing: SQL is used to coordinate data sharing by concurrent users, ensuring that they do not interfere with one another.

Data integrity: SQL defines integrity constraints in the database, protecting it from corruption due to inconsistent updates or system failures.

SQL is thus a comprehensive language for controlling and interacting with a database management system.

Informal Definitions

Informally, a relation looks like a table of values. A relation typically contains a set of rows. The data elements in each row represent certain

facts that correspond to a real-world entity or relationship– In the formal model, rows are called

tuples

Each column has a column header that gives an indication of the meaning of the data items in that column– In the formal model, the column header

is called an attribute name (or just attribute)

Example of a Relation

Relational Integrity Constraints Constraints are conditions that must hold

on all valid relation states. There are three main types of constraints

in the relational model:– Key constraints– Entity integrity constraints– Referential integrity constraints

Another implicit constraint is the domain constraint– Every value in a tuple must be from the domain of its attribute

(or it could be null, if allowed for that attribute)

STRUCTURED QUERY LANGUAGE SQL (Structured Query Language) is a database sub-language

for querying and modifying relational databases. It was developed by IBM Research in the mid 70's and

standardized by ANSI in 1986. Relational Model defines two root languages for accessing a

relational database -- Relational Algebra and Relational Calculus.

REFERENCES https://docs.oracle.com/cd/B19306_01/server.102/

b14220/intro.htm Oracle 11g with PL/SQL Approach by Sham Tickoo

and Sunil Raina

PRACTICAL IMPLEMENTATION

OF SQL COMMANDS AND ITS

VARIOUS TYPESWILL BE PERFORMED IN

LABS