Download ORACLE LECTURE SERIES

INTRODUCTION TO ORACLE
DATABASE ADMINISTRATION
Lynnwood Brown
President System Managers LLC
Introduction – Lecture 1
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INTRODUCTION TO DATABASES
Companies have information that must be captured
and stored. The information may include:
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Customer Billing
Payroll
Product orders
Services sold
Inventory
Bank account
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INTRODUCTION TO DATABASES
Types Of Databases
• Utility companies, banks, and airlines, mail order
businesses and pharmacies are examples of companies
that may use a database for Online Transaction
Processing (OLTP).
• OLAP database (data warehouse).
• Data warehouses do not contain mission-critical data and
as such do not require response times as quick as OLTP
databases.
• OLAP databases rely on complex queries that must take
millions of records into consideration for knowledge
discovery.
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INTRODUCTION TO DATABASES
In the 1960’s and 1970’s
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Automation of back-office
Ad-hoc transactions rather then batch transactions
Network Database Management System
Hierarchical Database Management System
Relational Database Management System
Information consist of data. The software that accesses the
data is the management system.
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INTRODUCTION TO DATABASES
Hierarchical Database
• A database management system that links records together
like a family tree such that each record type has only one
owner, e.g. an order is owned by only one customer.
• Hierarchical structures were widely used in the first mainframe
database management systems.
• Creates repetition of data within the database
• Hard to relate structures that exist in the real world
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Hierarchical RDBMS
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INTRODUCTION TO DATABASES
Network Database
• A database management system in which each record type can
have multiple owners, e.g. orders are owned by both customers
and products. This contrasts with a hierarchical database (one
owner) or relational database (no explicit owner).
• Designed to solve the problem of data redundancy by
representing relationships in terms of sets rather than a
hierarchy.
• Similar to the hierarchical model (subset of the network model).
Instead of using a single-parent tree hierarchy, the network
model uses set theory to provide a tree-like hierarchy with the
exception that child tables were allowed to have more than one
parent.
This allowed
network
model
many-toCopyright
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allsupport
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many relationships.
Network RDBMS
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INTRODUCTION TO DATABASES
Relational Database
• A relational database allows the definition of data structures,
storage and retrieval operations and integrity constraints. In
such a database the data and relations between them are
organized in tables.
• A table is a collection of records and each record in a table
contains the same fields.
• Certain fields may be designated as keys, which means that
searches for specific values of that field will use indexing to
speed them up.
• Everything
within
the relational
can
stored
in tables.
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reserved.
RELATIONAL DATABASE VENDORS
Several companies have relational database products. These
products include:
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Oracle RDBMS
Sybase
Informix
DB2 (IBM)
Microsoft SQL-Server
Red Brick
Microsoft ACCESS
MySQL
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ORACLE PRODUCTS SUMMARY
Oracle offers many products
• The main product is the Relational DataBase
Management System.
• The Oracle RDBMS is based on the research paper “A
Relational Model of Data for Large Shared Databanks”
written by the IBM mathematician Dr. Ted Codd.
• Oracle offers several products designed for application
development and end user support.
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ORACLE PRODUCT SUMMARY cont.
Application
Development Tools
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CASE*Dictonary
CASE*Designer
CASE*Generator
Oracle Graphics
Oracle Terminal
SQL*PLUS
Oracle*FORMS
Oracle*REPORTS
Oracle Precompilars
Manuf acturing
Applications
Financial Applications
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Oracle
Oracle
Oracle
Oracle
General Ledger
Purchasing
Payables
Assest
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Oracle
Oracle
Oracle
Oracle
Oracle
Work In Progress
Costing
Bills of Materials
Engineering
Master Scheduling
Human Resource
Applications
SQL
Database Utilities
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Enterprise Manager
Server Manager
Export/Import
SQL*Loader
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Oracle
Oracle
Oracle
Oracle
Oracle
Human Resources
Payroll
Training Administrator
Time Management
WEB Employees
Oracle Server
and
Intergrated
Data Dictionary
Oracle Projects
PL/SQL
* Oracle Project Costing
* Oracle Project Billing
* Oracle Personal Time and
Expense
* Oracle Activity Management
Gatew ay
Oracle Value-A dded
Solutions
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CAD/CAM/CIM/CAE
Retail
Distribution
Project Management
Oracle Sales Force
Automation
Connectivity Products
* SQL*NET
* SQL*Connect
* Netw ork Manager
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Oracle
Oracle
Oracle
Oracle
Oracle
Service
Sales and Marketing
Sales Compensation
Self Service
Financial Analyzer
ORACLE PRODUCTS cont.
• The Oracle RDBMS is used as a data repository.
• End user programs communicate with the Oracle
RDBMS through Oracle’s communication
product NET8.
• Client applications can be developed using
various applications development tools (Visual
Basic, PowerBuilder, PRO*C, OCI etc...)
• Client application software generates SQL and
PL/SQL to communicate with the RDBMS.
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Structured Query Language
All relational databases use SQL
Basic SQL Commands
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SELECT – To get data from a database table
INSERT – To place new data into the database table
UPDATE – Modify existing data
DELETE – Remove data
ALTER – Modify a database objects structure
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THE ORACLE RDBMS ARCHITECTURE
The Oracle RDBMS is separated into two distinct parts.
The Oracle instance and the Oracle database.
RDBMS ARCHCITECTURE cont.
• The Oracle instance includes the Oracle
background processes (PMON, SMON, DBWR,
LGWR, TNSLSNR etc...) and a group of buffers
called the System Global Area
• The database consist of the data files, log files
and initialization files that are stored on the disk.
• The Oracle RDBMS consist of the instance and
the database.
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RDBMS ARCHITECTURE cont.
• Data files are the physical entity that makes up
the logical entity called the tablespace.
• The database will consist of at least one
tablespace called the SYSTEM tablespace.
• The SYSTEM tablespace contains the data
dictionary.
• User data (tables, views, indexes, synonyms etc..)
should never be stored in the SYSTEM
tablespace.
• End users are assigned to a default tablespace.
• All database objects are stored in a tablespace.
RDBMS ARCHITECTURE cont.
• Oracle represents tables and indexes as segments.
• There are four types of Oracle segments. Table,
index, temporary and rollback or UNDO
segments.
• Segments consist of extents. Extents consist of
data blocks.
• The finest granularity is the Oracle data block.
• The Oracle data block size should be some
multiple of the operating system block-size.
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RDBMS ARCHITECTURE cont.
• Oracle Data file Layout
RDBMS ARCHITECTURE cont.
• There are three other types of files. They are log
files, control files and initialization files
• Log files contain data used for database recovery.
• Control files contain information concerning the
database creation and organization.
• Initialization files contain the database tuning
parameters and various database startup
parameters.
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RDBMS ARCHITECTURE cont.
• The Oracle memory structure called the System
Global Area contains the various Oracle database
buffers.
• The SGA contains the database buffer cache,
redo log buffer, data dictionary cache, the library
cache and the sort area.
• The data dictionary cache and the library cache
are often refereed to as the shared pool.
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RDBMS ARCHITECTURE cont.
• Unit for SGA allocation is called a 'Granule'
• A granule is a unit of contiguous virtual memory
• Granule size = 4MB if the SGA size is less than
128MB
• Granule size = 16MB if the SGA size is greater
than 128MB
• The maximum size of the SGA is controlled by
the database initialization parameter
SGA_MAX_SIZE
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RDBMS ARCHITECTURE cont.
• There are several Oracle processes.
• There are four main processes are DataBase
WRiter, LoG WRiter, System MONitor and
Process MONitor.
• The Oracle communication process TNSLSNR.
• The ARCH process is used for automatic
archiving of redo log files.
• The CKPT process is used to flush data from the
buffers to the data files (checkpoint).
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RDBMS ARCHITECTURE cont.
On the Windows Platform:
• Oracle runs as a single process.
• The Oracle process will create multiple threads
• Oracle runs as a Windows service.
• Various Oracle “keys” are stored in the Windows
registry.
• Supports the Intel ESMA (Extended Server
Memory Architecture), which allows Oracle
to access more than the 3GB of physical
memory
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Oracle Single Executable On Windows
Oracle Service On Windows
RDBMS ARCHITECTURE cont.
On the UNIX Platform:
• Oracle executable creates multiple
processes.
• Requires a pre-allocated UNIX memory
area to store the SGA.
• Support for most versions of UNIX and
Linux
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Oracle Memory Structure On UNIX
RDBMS ARCHITECTURE SUMMARY
• Oracle Corporation makes many products. The
central product is the RDBMS.
• Oracle’s RDBMS is divided into two parts. One
part is called the instance and the other part is
called the database.
• The instance consist of the various processes and
memory structures.
• The database consist of the data files, log files,
control files and the initialization file called
init<SID>.ora.
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