Oracle is one of the most widely-used relational database management systems in the world, and a popular choice for enterprise-level applications due to its scalability, performance, and reliability.
Understanding the fundamentals of Oracle is essential for anyone looking to work with this technology, and this article provides an overview of the key concepts, tools, and features of Oracle for beginners.
From the basic architecture and components of Oracle databases, to more advanced topics such as security, high availability, and cloud-based services, this article will provide a solid foundation for those who are new to Oracle.
Introduction to Oracle Database Architecture
Oracle Database is a highly scalable and reliable relational database management system. Its architecture is designed to handle large amounts of data and provide high availability and security. In this section, we'll cover an overview of the Oracle Database architecture, the different database models, and the hardware and software requirements needed to run Oracle Database.
Overview of Oracle Database Architecture
The Oracle Database architecture consists of several components that work together to manage and store data. The main components are the Oracle Database software, the instance, and the memory structures. The Oracle Database software is responsible for managing the data and the instance creates a connection between the software and the database. The memory structures manage the data cache and control the database's operation.
Oracle Database Models
Oracle Database supports several data models, including relational, object-oriented, and hierarchical models. The relational model is the most commonly used and is based on tables with columns and rows. The object-oriented model stores data as objects, while the hierarchical model organizes data in a tree-like structure.
Hardware and Software Requirements
To run Oracle Database, you'll need a suitable hardware and software environment. The hardware requirements will depend on the size of the database and the anticipated workload. The software requirements include an installation of Oracle Database and an operating system that is supported by the database.
Key Features and Benefits of Oracle Database
Oracle Database has several key features and benefits that make it a popular choice for enterprise-level organizations. In this section, we'll cover the scalability and performance, reliability and availability, and security and compliance of Oracle Database.
Scalability and Performance
Oracle Database is designed to scale horizontally and vertically, allowing organizations to accommodate growing data needs. It also has built-in performance optimization tools that can improve query execution times and overall database performance.
Reliability and Availability
Oracle Database is known for its high reliability and availability. It has built-in mechanisms for data recovery and backups, and it can handle hardware and software failures without interrupting operations.
Security and Compliance
Oracle Database provides advanced security features, such as encryption, access control, and auditing, to protect against unauthorized access and data breaches. It is also compliant with regulatory standards, including GDPR, HIPAA, and SOX.
Oracle Database Components and Tools
Oracle Database has several components and tools that help manage and control the database's operation. In this section, we'll cover the Oracle Database instance, memory structures, and control and management tools.
Oracle Database Instance
The Oracle Database instance is the set of memory structures and processes that manage the database's operation. It includes the system global area (SGA), the program global area (PGA), and the background processes that perform maintenance tasks.
Oracle Database Memory Structures
The Oracle Database memory structures manage the data cache and control the database's operation. The SGA is the primary memory structure and stores shared memory areas, such as buffer cache, shared pool, and redo log buffer.
Oracle Database Control and Management Tools
Oracle Database provides several control and management tools, including Oracle Enterprise Manager (OEM), SQL Developer, and SQL*Plus. These tools can help manage the database's operation, monitor performance, and perform maintenance tasks.
Understanding SQL and PL/SQL in Oracle
SQL and PL/SQL are core components of Oracle Database and are essential for managing and querying data. In this section, we'll cover an introduction to SQL, PL/SQL programming fundamentals, and stored procedures, functions, and triggers.
Introduction to SQL
SQL (Structured Query Language) is a standard language for managing and querying data in a relational database. It allows users to perform operations such as selecting, inserting, updating, and deleting data from tables.
PL/SQL Programming Fundamentals
PL/SQL (Procedural Language/Structured Query Language) is a powerful programming language that is used to write complex queries and stored procedures. It is a block-structured language that allows users to define variables, loops, and conditions within a program.
Oracle Stored Procedures, Functions, and Triggers
Oracle Database supports stored procedures, functions, and triggers, which are pre-written programs that can be executed with specific parameters. Stored procedures and functions are used to perform complex operations, while triggers are used to automatically execute a set of actions when a specific event occurs.
FAQ:
What is Oracle, and what is it used for?
Oracle is a relational database management system (RDBMS) that is designed to store, organize, and retrieve large amounts of data. It is used by organizations to manage enterprise-level applications, such as financial management, human resources, and customer relationship management.
What are the benefits of using Oracle?
Oracle offers a wide range of benefits, including high performance, scalability, and reliability. It also offers advanced security features to protect sensitive data, and supports a variety of operating systems and platforms. Additionally, Oracle provides a range of tools and features for managing and optimizing databases.
What are some common tools used for administering Oracle databases?
Oracle provides a range of tools for administering databases, including Oracle Enterprise Manager, SQL*Plus, and the Oracle Universal Installer. These tools are used for tasks such as monitoring database performance, managing database users and permissions, and backing up and restoring databases.
Can you suggest some effective methods to ensure the security of Oracle databases?
To secure Oracle databases, it is important to use strong passwords, limit access to sensitive data, and regularly monitor database activity. Additional best practices include keeping software up to date, applying security patches promptly, and implementing encryption for sensitive data. It is also important to have a disaster recovery plan in place in case of data loss or breach.
Queries :
|
DDL: Data Definition Language |
|
create |
|
alter |
|
drop |
|
DML: Data Manipulation Language |
|
insert |
|
update |
|
delete |
|
DCL: Data Control language |
|
commit |
|
rollback |
|
savepoint |
|
DAL: Data Access Language |
|
grant |
|
revoke |
mysql datatype------int , double , char , float , file , text , blob , clob
syntax:---------
(
col1_name datatype(size),
col2_name datatype(size),
-----
-----
);
In mysql:------
exp:----
create table student
(
sid int,
sname char(15),
dob date,
feebal double,
phone int
);
mysql> desc student;
sname char(15) YES NULL
feebal double YES NULL
phone int(11) YES NULL
insert into student values(101,'raman','1984-04-21',199.89,159);
insert into student values(102,'suman','1987-09-13',190.82,198);
insert into student values(103,'radha','1989-10-30',99.59,456);
100| rajiv 1982-01-23 199.81 123
101 raman 1984-04-21 199.89 159
102 suman 1987-09-13 190.82 198
103 radha 1989-10-30 99.59 456
column & insert data in the same order .it will take corresponding field value and which will not
putting into the table will show as null(default)
insert into student(sid,sname,phone)values(222,'mohan',999);
insert into student(sname,dob,feebal)values('gandhi','2008-09-16',111.77);
sid sname dob feebal phone
100 rajiv 1982-01-23 199.81 123
101 raman 1984-04-21 199.89 159
102 suman 1987-09-13 190.82 198
103| radha 1989-10-30 99.59 456
111 ganesh NULL 111.77 NULL
222 mohan NULL NULL 999
NULL gandhi 2008-09-16 111.77 NULL
Query OK, 1 row affected (0.02 sec)
Rows matched: 1 Changed: 1 Warnings: 0
333 rajiv 1982-01-23 199.81 888
101 raman 1984-04-21 199.89 159
102 suman 1987-09-13 190.82 198
103| radha 1989-10-30 99.59 456
111 ganesh NULL 111.77 NULL
222 mohan NULL NULL 999
NULL gandhi 2008-09-16 111.77 NULL
Query OK, 1 row affected (0.03 sec)
Query OK, 6 rows affected (0.02 sec)
Empty set (0.00 sec)
(
sid number(10),
sname char(15),
dob date,
feebal number(6,2),
phone number
);
Name Null? Type
SID NUMBER(10)
SNAME CHAR(15)
DOB DATE
FEEBAL NUMBER(6,2)
PHONE NUMBER
insert into student values(101,'raman','10-jan-1984',199.89,159);
insert into student values(102,'suman','10-jan-1987',190.82,198);
insert into student values(103,'radha','10-jan-1989',99.59,456);
---------- --------------- ---------------- ---------- ----------
100 rajiv 10-JAN-82 199.89 123
100 rajiv 10-JAN-82 199.81 123
101 raman 10-JAN-84 199.89 159
102 suman 10-JAN-87 190.82 198
103 radha 10-JAN-89 99.59 456
of the type character & date must be enclosed b/w single quotation mark(' ')
is not require for number type.
exp:----
date format in Oracle:--- DD/MM/YYYY----23-jan-1998
column & insert data in the same order. it will take corresponding field value and which will not
putting into the table will show as null(default) .
insert into student(sid,sname,phone)values(222,'mohan',999);
insert into student(sname,dob,feebal)values('gandhi','31-mar-2008',111.77);
---------- --------------- -------------- ---------- ----------
100 rajiv 10-JAN-82 199.89 123
100 rajiv 10-JAN-82 199.81 123
101 raman 10-JAN-84 199.89 159
102 suman 10-JAN-87 190.82 198
103 radha 10-JAN-89 99.59 456
111 ganesh 111.77
222 mohan 999
gandhi 31-MAR-08 111.77
attributes:---- sid,sname,dob,feeebal,phone
we can update, insert or delete only one row or column at a time for multiple updating ,deletion or insertion
we have to write multiple query.
update table_name set col1=val1,col2=val2------
where condition;
SQL> select * from student;
---------- --------------- --------------- - --------- ----------
333 rajiv 10-JAN-82 199.81 888
101 raman 10-JAN-84 199.89 159
102 suman 10-JAN-87 190.82 198
103 radha 10-JAN-89 99.59 456
111 ganesh 111.77
222 mohan 999
gandhi 31-MAR-08 111.77
syntax:---
delete from table_name where condition;
exp:---
delete from student where sid=101;
delete from student; /* deleting all row.
---------- --------------- ------------- ---------- ----------
333 rajiv 10-JAN-82 199.81 888
102 suman 10-JAN-87 190.82 198
103 radha 10-JAN-89 99.59 456
111 ganesh 111.77
222 mohan 999
gandhi 31-MAR-08 111.77
syntax:----
drop table table_name;
drop table student;