INTRODUCTION TO DBMS ENVIRONMENT

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INTRODUCTION TO DBMS ENVIRONMENT

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DBMS Defined

• SOFTWARE THAT FACILITATES THE PROCESSES OF
• Defining
• Constructing
• Maintaining database for various apps.
• Relational database
• Implemented through the use of RDBMS

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RDBMS Services

• Data definition for defining and storing DB
  objects
• Data maintenance for rows (records)
• Data manipulation for
• Inserting, updating, deleting, sorting data
• Data integrity for ensuring data accuracy
• Data security
• Database backup and recovery mechanisms

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Database Models

• Three Types of Implementation Database Models
• Hierarchical database model
• Network database model
• Relational database model

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Database Models

• Hierarchical Database Model (ex3)
• Background
• GUAM (Generalized Update Access Method) was
  developed by North American Rockwell.
• It conformed to upside-down tree structure --
  hierarchical structure.
• Information Management System (IMS) -- Jointly
  developed by IBM and Rockwell.
• Hierarchical database model concepts for the
  basis for subsequent database development.
• Its limitations lead to a different way of
  looking at database design.

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Hierarchical Database Model

• Advantages
• Data sharing and security provision
• Data independence -- Reduced programming and
  maintenance effort
• Database integrity
• Efficiency dealing with a large database
• Fast access (but only if accessing data from the
  top of the hierarchy)
• Disadvantages
• Requirement of knowledge of physical level of
  data storage
• Inability to represent relationships that do not
  conform to the hierarchical 1M standard (also,
  each child can only have 1 parent)
• Complex and inflexible to manage
• Time consuming and complicated application
  programming
• Difficult to search for records in the bottom or
  middle of the hierarchy
• Lack of ad hoc query capability for end users

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Database Models

• Network Database Model (ex)
• Background
• CODASYL (Conference on Data Systems Language)
  group created DataBase Task Group (DBTG) in 1971.
• Three DBTG data management language components
• Schema Data Definition Language (DDL)
• Subschema Data Definition Language
• Data Manipulation Language
• ANSI SPARC (Standards Planning And Requirements
  Committee) augmented the database standards in
  1975.

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Network Database Model

• Advantages
• Easier implementation of MN relationships
• Superior data access type and flexibility
• Enforced data integrity
• Sufficient data independence
• Disadvantages
• Difficult to design and use properly
• Difficult to make changes in a database
• Very complex structure from the application
  programmers point of view
• Complex navigational data access environment

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Database Models

• Relational Database Model
• Background
• E. F. Codd developed the relational model in
  1970.
• Based on mathematical set theory
• Uses a relation as the building block of the
  database
• Each relation is represented by a two-dimensional
  file structure known as a table
• User does not need to know the mathematical
  details of data retrieval or the physical aspects
  of data storage
• Conceptually simple but versatile
• Major breakthrough for both users and designers
• Requires more computing power
• Considered impractical in the 1970s
• Modern computers (even PCs) are powerful enough
  to handle relational databases.

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Relational Database Model

• Basic Structure
• Relational Database Management System (RDBMS)
• RDBMS allows user/designer operate in a human
  logical environment.
• Relational database is perceived by the user as a
  collection of tables in which data are stored.
• Each table consists of series of row/column
  intersections.
• Tables are not physically connected.
• Tables (or relations) are related to each other
  by sharing a common entity characteristic (I.e.,
  column).
• The relationship type is often shown in a
  relational schema.
• A table yields complete data and structural
  independence because it is a purely logical
  structure.

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Relational Database Model

• Advantages
• Data independence and structural independence
• Easy to design the database and to manage its
  contents
• Less programming effort required
• Powerful and flexible query capability
• Structured Query Language (SQL)
• Fourth Generation Language (4GL)
• Specify what to do not how to do
• Introduced by IBM in 1974
• 3 parts (1) User interface, (2) Set of tables
  (3) SQL engine
• Disadvantages
• RDBMS requires substantial hardware and operating
  system overhead.
• It tends to be slower than other database
  systems.

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INTRODUCTION TO SQL SERVER 2005 DBMS

• Features
• Components

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SQL Server 2005 Features

• Internet standard support
• Uses MS .Net technology for data exchange across
  the Internet (including XML support)
• Scalability
• Used for large, multiprocessor systems
• Security, backup and recovery, storage space
  management, open connectivity, tools and
  applications

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SQL Server 2005 Components

• Database server
• Provides database management services
• Desktop version of SQL Server
• MS SQL Server 2005 Desktop Engine (MSDE)
• SQL Server Service Manager shows the status of
  the database engine
• Client tools
• Let you work with the database and the data it
  contains

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SQL Server 2005 Components

• Summary of the client tools
• Books online
• Provide online help documentation
• Client Network Utility
• Manages the client Net-Libraries that provide
  communication with different network protocols
• Configure SQL XML
• Used to define and register a new virtual
  directory on a web server running Internet
  Information Services
• Support in IIS
• To enable SQL Server databases accessed using
  HyperText Transfer Protocol (HTTP)

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SQL Server 2005 Components

• Summary of the client tools
• Enterprise Manager
• Used to administer SQL Server databases lets you
  work with one or more instances of SQL server
• Import and Export Data
• Launches a wizard to help import, export and
  transform data and objects from various sources
• Profiler
• Captures SQL Server events for the analysis and
  improvement in query performance
• Query Analyzer
• Used to design and test SQL statements and
  scripts interactively lets you work with a
  single instance of SQL server