CH15.ppt

1515Chapter 15Database AdministrationChapter 15Database Administration

Database Systems: Design, Implementation, and Management4th Edition

Peter Rob & Carlos Coronel

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Data as a Corporate AssetData as a Corporate Asset

Data were seldom viewed as a company asset for two reasons:

There were simply too many data to be processed manually

Internal and external business operations moved at a much slower pace than they do today, so there was relatively little need for quick reactions triggered by fast-flowing information.

The computer liberated both managers and data. Data are now better understood as a resource.

An organization is subject to a data-information-decision cycle. (Figure 15.1)

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The Data-Information-Decision Cycle

Figure 15.1

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The Need for and Roleof Databases in an Organization


Used properly, the DBMS facilitates: Interpretation and presentation of data in useful

formats, by transforming raw data into information. Distribution of data and information to the right people

at the right time. Data preservation and data usage monitoring for

adequate periods of time. Control over data duplication and use, both internally

and externally.

The database’s predominant role is to support managerial decision making at all levels in the organization.

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DB Support at Different Management Levels

Top Management Level

Provide the information necessary for strategic decision making, strategic planning, policy formulation, and goals definition.

Provide access to external and internal data to identify growth opportunities and to chart the direction of such growth.

Provide a framework for defining and enforcing organizational policies.

Improve the likelihood of a positive return on investment for the company by searching for new ways to reduce costs and/or by boosting productivity.

Provide feedback to monitor whether the company is achieving its goals.

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Middle Management

Deliver the data necessary for tactical decisions and planning.

Monitor and control the allocation and use of company resources

– How efficiently are resources allocated and used?

– What potential or current operational problems exist?

– Evaluate the performance of the different departments.

Provide a framework for enforcing and ensuring the security and privacy of the data in the database.

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Operational Management

Represent and support the company operations as closely as possible.

Produce query results within specified performance levels.

Enhance the company’s short-term operational ability by providing

– Timely information for customer support

– Support for application development and computer operations.

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Introduction of a Database:Special Considerations

Introduction of a Database:Special Considerations

The introduction of a DBMS represents a big change and challenge and is likely to have a profound impact throughout the organization.

The main issue of the DBMS should be the organization’s needs rather than the DBMS’s technical virtues.

Three important aspects:

Technological: DBMS hardware and software

Managerial: Administrative functions

Cultural: Corporate resistance to change

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The Evolution of the Database Administration Function


Electronic Data Processing (EDP) Department

Data process (DP) department

Its task was to pool all computer resources to support all departments at the operational level with a minimal duplication of data and effort.

The DP department was in charge of coordinating and maintaining all operational applications.

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Information Systems (IS) Department

IS responsibilities were broadened to include:

A service function to provide end users with active data management service.

A production function to provide end users with specific solutions for their information needs.

The database administration function was created to handle increasingly complex data management tasks.

The person responsible for the control of the centralized and shared database was the database administrator (DBA).

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The IS Department Internal Organization

Figure 15.2

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The Placement Of The DBA Function

Figure 15.3

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Factors Affecting the Placement of DBA Company management style Size and complexity of the company operations Geographic distribution of the company facilities

Changes in DBMS Technologies Affecting Organizational Styles The development of distributed databases The growing use of Internet-ready and object-oriented

databases and the growing number of data warehousing applications

The increasing sophistication and power of microcomputer-based DBMS.

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DBA Activities Database planning

Database requirements-gathering and conceptual design

Database logical design and transaction design

Database physical design and implementation

Database testing and debugging

Database operations and maintenance, including installation, conversion, and migration

Database training and support

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A DBA Functional Organization

Figure 15.4

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The general coordinator of all DBAs is known as the systems administrator (SYSADM). (Figure 15.5)

Some large corporations make a distinction between a DBA and the data administrator (DA).

The DA, a.k.a., the information resource manager (IRM), usually reports directly report to top management and is given a higher degree of responsibility and authority than the DBA.

The DA is responsible for controlling the overall corporate data resource, both computerized and non-computerized.

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Multiple Database Administrators In An Organization

Figure 15.5

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Contrasting DA And DBA Activities And Characteristics

Table 15.1

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A Summary Of DBA Activities

Figure 15.6

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Desired DBA Skills

Table 15.2

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Human ComponentHuman Component

The DBA’s Managerial Role Coordinating, monitoring, and allocating DB

administration resources: people and data. Defining goals and formulating strategic plans for

the DB administration function.

Table 15.3 DBA Activities And Services

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Human ComponentHuman Component End User Support

User requirements-gathering Conflict and problem resolution Finding solutions to information needs Ensuring quality and integrity of application and data Building end user confidence Managing the training and support of DBMS users

Policies, Procedures, and Standards Policies are general statements of direction or action that

communicate and support the DBA goals. Standards are more detailed and specific than policies and

describe the minimum requirement of a given DBA activity. Procedures are written instructions that describe a series

of steps to be followed during the performance of a given activity.

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Human ComponentHuman Component Data Security, Privacy, and Integrity

Authorization management defines procedures for the following functions:– User access management– View definition– DBMS utilities access control– DBMS usage monitoring

Security breaches can yield a database whose integrity is either preserved or corrupted:– Preserved: Action is required to avoid the repetition

of similar security problems, but data recovery may not be necessary.

– Corrupted: Action is required to avoid the repetition of similar security problems, and the database must be recovered to a consistent state.

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Human ComponentHuman Component Data Backup and Recovery

The database security officer (DSO) is responsible for the assurance of the database security and integrity.

Disaster management includes all planning, organizing, and testing of database contingency plans and recover procedures.

– Periodic data and applications backups

– Proper backup identification

– Convenient and safe backup storage

– Physical protection

– Personal access control

– Insurance coverage for the data in the database

Data Distribution and Use

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The DBA’s Technical Role

DBMS and utilities evaluation, selection, and installation

Design and implementation of databases and applications

Testing and evaluation of databases and applications

Operation of the DBMS, utilities, and applications

Training and supporting users

Maintenance of the DBMS, utilities, and applications

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DBMS and Utilities Evaluation, Selection, and Installation


DBMS model

DBMS storage capacity

Application development support

Security and integrity

Backup and recovery

Concurrency control

Performance

Database administration tools

Interoperability and data distribution

Portability and standards

Hardware

Data Dictionary

Vendor training and support

Available third-party tools

Cost

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Human ComponentHuman Component Design and Implementation of Databases and

Applications

Data modeling and design services at conceptual, logical, and physical levels

Review of the design to ensure that transactions are:

– Correct: The transactions mirror real-world events.

– Efficient: The transactions do not overload the DBMS.

– Compliant with integrity and standards.

Database storage and access plans

Database operational procedures

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Testing and Evaluation of Databases and Applications

Technical aspects of both the applications and the database

Evaluation of the written documentation

Observance of standards for naming, documenting, and coding

Data duplication conflicts with existing data

The enforcement of all data validation rules

Operation of the DBMS, Utilities, and Applications

System Support

Performance monitoring and tuning

Backup and recovery

Security auditing and monitoring

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Human ComponentHuman Component Training and Supporting Users

Training users and application programmers to use the DBMS and its tools

Unscheduled, on-demand technical support for end user and programmers

External sources (e.g., vendors) for support

Maintenance of the DBMS, Utilities, and Applications

Management of the physical storage devices

Upgrading the DBMS and utility software

Migration and conversion services for incompatible data and different DBMS

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Database Administration ToolsDatabase Administration Tools

The Data Dictionary

Different types of data dictionaries:

An integrated data dictionary is included with the DBMS, while a stand-alone data dictionary comes from a third-party vendor.

An active data dictionary is automatically updated by the DBMS, while a passive data dictionary requires a batch process to create and update the dictionary.

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The Data Dictionary The data dictionary typically stores descriptions of all:

Data elements defined in all tables of all databases

Tables defined in all databases

Indexes defined for each database table

Defined databases

End users and administrators of the database

Programs that access the database

Access authorizations for all users of all databases

Relationships among the data elements

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Data Dictionary Usage Examples: Example 1

List the names and creation dates of all tables created by the user JONESVI in the current database.

SELECT NAME, CTIMEFROM SYSTABLESWHERE CREATOR = ‘JONESVI’;

Example 2List the names of the columns for all tables created by JONESVI in the current database.

SELECT NAMEFROM SYSCOLUMNSWHERE CREATOR = ‘JONESVI’;

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Database Administration ToolsDatabase Administration Tools Example 3

List the names of all tables for which the user JONESVI has DELETE authorization.

SELECT NAMEFROM SYSTABAUTHWHERE GRANTEE = ‘JONESVI’;

AND DELETEAUTH = ‘Y’;

Example 4List the names all users who have some type of authority over the INVENTRY table.

SELECT DISTINCT GRANTEEFROM SYSTABAUTHWHERE TTNAME = ‘INVENTRY’;

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Database Administration ToolsDatabase Administration Tools Example 5

List the user and table names for all users who can alter the database structure for any table in the database.

SELECT GRANTEE, TTNAMEFROM SYSTABAUTHWHERE ALTERAUTH = ‘Y’ORDER BY GRANTEE, TTNAME;

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CASE Tools

CASE -- Computer-Aided Software Engineering

It provides an automated framework for the Systems Development Life Cycle.

Front-end CASE tools provide support for the planning, analysis, and design phases.

Back-end CASE tools provide support for the coding and implementation phases.

It is based on the use of structured methodologies and powerful graphical interfaces.

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Benefits of CASE tools

A reduction in development time and costs

The automation of the SDLC

Standardization of the systems development methodologies

Easier maintenance of application systems developed with CASE tools.

Improve communications among the DBA, applications designers, and the end users.

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Database Administration ToolsDatabase Administration Tools Commercial CASE Tools

Excelerator from Merant, Inc. provides five components:

– Graphics designed to produce structured diagrams as data flow diagrams and E-R diagrams.

– Screen painters and report generators to produce the information system’s input/output formats.

– An integrated repository for storing and cross-referencing the system design data.

– An analysis segment to provide a fully automated check of system consistency, syntax, and completeness.

– A program document generator.

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An Example of a CASETool’s Use: Excelerator

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Commercial CASE Tools

PLATINUM ERwin by PLATINUM Technology

It produces fully documented E-R diagrams that can be displayed at different abstraction levels.

It is able to produce detailed relational designs.

Major relational DBMS vendors, such as ORACLE, provide fully integrated CASE tools for their own DBMS software as well as for RDBMSs supplied by other vendors.

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Developing a Data Administration Strategy


Information Engineering allows us to translate the strategic goals of the company into the data and applications.

IE focuses on the description of the corporate data instead of the processes.

The output of the IE process is an Information Systems Architecture (ISA) that serves as the basis for planning, development, and control of future information systems. (Figure 15.8)

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Forces Affecting The Development Of The ISA

Figure 15.8

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Critical Success Factors for IS Strategy

Management commitment

Thorough company situation analysis

End user involvement

Defined standards

Training

A small pilot project

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Database Administration Using Oracle


Detailed look at how a DBA might handle the following technical tasks in a specific DBMS - Oracle Workgroup 2000 for Windows NT:

Creation and expansion of the database storage structures.

Management of database objects such as tables, indexes, triggers, procedures, and so on.

Management of the end user database environment, including the type and extent of database access.

Customization of database initialization parameters.

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Oracle Database Administration Tools

Security Manager

Schema Manager

Storage Manager

SQL Worksheet

Instance Manager

Figure 15.9 The Oracle Administrator Toolbar

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The Default Login

Figure 15.10 Oracle Login Information

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Ensuring an Automatic RDBMS Start

Figure 15.11 Verifying That The Oracle Services Are Running

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Using the Storage Manager to Create Tablespaces and Datafiles

A database is logically composed of one or more tablespaces. A tablespace is a logical storage space. Tablespaces are primarily used to logically group related data.

The tablespace data are physically stored in one or more datafiles. A datafile physically stores the database’s data.

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When the DBA creates a database, Oracle automatically creates the tablespaces and datafiles shown in Figure 15.12:

The SYSTEM tablespace is used to store the data dictionary data.

The USER_DATA tablespace is used to store the table and to index data created by the end users.

The TEMPORARY_DATA tablespace is used to store the temporary tables and indexes created during the execution of SQL statements.

The ROLLBACK_DATA tablespace is used to store database transaction recovery information.

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Using the Storage Manager, the DBA can

Create additional tablespaces to organize the data in the database.

Create additional tablespaces to organize the different subsystems that may exist within the database.

Expand the tablespace storage capacity by creating additional datafiles.

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The Oracle Storage Manager

Figure 15.12

1515Figure 15.13Creating a New Tablespace

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The Oracle Schema Manager

Figure 15.14

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Figure 15.15 The Oracle Security Manager

1515Figure 15.16The Create User Dialog Box

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Creating A New Database With The Oracle Instance Manager

Figure 15.18

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New Instance Screen

Figure 15.19

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Advanced Parameters Screen

Figure 15.20

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