chapter 10 exam 2

Relational DBMS Catalogs

A highly active but limited-scope data diction- ary that is very closely tied in to the operations of the relational DBMS and supports the relational query optimizer. Composed of relational tables that may be queried with standard SQL commands. • Included: databases, tables, attributes, views, indexes, disks, users. Not included: reports and non-relational files. Provides a roadmap through the database data for exploring new ways to use the data

Data Repositories

A large-scale data dictionary that includes entity types generated and needed by the latest IS technologies. In the CASE environment, the data repository holds the same types of data that traditional data dictionaries hold, as well as CASE-specific data such as reusable code modules

Data Administration

A planning and analysis function that is responsible for: • Setting data policy and standards. • Promoting the company's data as a competitive resource. • Accounting for the use of data. • Providing liaison support to systems analysts during application development. More operationally oriented. Responsible for the day-to-day monitoring and management of the company's various active databases. Responsible for providing liaison support to program designers during application development. Carries out many of the policies set by data administration.

Data Ownership

As a resource of value to the company, the data "belongs" to the company but, practically, data is controlled by its user or primary user. If ownership has been established and a new application requires the use of existing data, then it is the job of data administration to act as an intermediary and approach the owner of the data with the request for data sharing. If there is a dispute over data sharing, then the data administration group acts as an arbitrator between the disagreeing parties.

Operational Management of Data

At the operational level, for the day-to-day management of the company's production databases, an independent department must be responsible. Data should be managed by an independent group whose loyalty is to the overall company and not to any individual function.

Data Planning

Begins with determining what data will be needed for future company business efforts and the applications that will support them. Related to strategic data planning is the matter of what hardware and software will be needed to support the company's information systems operations in the future

The Responsibilities of Database Administration

DBMS performance monitoring. DBMS troubleshooting. DBMS usage and security monitoring. Data dictionary operations. DBMS data and software maintenance. Database design.

Training

Data administration may be responsible for training all those in the company who have a reason to understand the company's data and, in some cases, the DBMS environment.

Liaison to Systems Analysts and Programmers

Data administrators are responsible for providing support to the systems analysts and programmers in all matters concerning the data needed by an application. Data administrators are generally involved in database design at some level, but the decision of what that precise level of involvement should be is dependent on a number of factors.

Advantages of Data and Database Administration

Data as a shared corporate resource. Efficiency in job specialization. Operational management of data. Managing externally acquired databases. Managing data in the decentralized environment.

Data's Competitive Advantage

Data can provide a competitive advantage for the company. Data administrators are in a unique position to understand how the company "works". It is the responsibility of the data administration function to respond to questions about how the company's business procedures can be ad- justed or modified to improve the company's operating efficiency.

The Responsibilities of Data Administration

Data coordination. Data planning. Data standards. Liaison to systems analysts and programmers. Training. Arbitration of disputes and usage authorization. Documentation and publicity. Data's competitive advantage.

Data Dictionary: Entities and Attributes

Data-Related Entities: • Databases, tables, attributes, web pages. Software-Related Entities: • Application programs, database management systems. Hardware-Related Entities: • Computers, disks, local area networks. Outputs: • Reports, queries. People

DBMS Usage and Security Monitoring

Database administrators keep track of which applications are running in the database environment and can track who is accessing the data in the database at any moment. Security: making sure that only authorized personnel access the data.

Managing Data in the Decentralized Environment

Decentralization is a fact of life to a greater or lesser degree in virtually all companies. Permits user departments in the company to handle some or all of their information systems needs on their own, without having to rely on the central information systems organization. Most companies have a hybrid centralized/ decentralized environment. Data and database administration are as important in a decentralized environment as in a centralized one for coordination purposes.

Data Standards

For example, controlling the way that attribute names, table names, and other data related names are formed. For example, insisting on consistency in the way the programs that access the database are written.

Data Coordination

In the centralized/decentralized environment, with data and copies of data scattered among mainframe computers, local area network servers, and even PCs, the possibility of inconsistency and error increases. Data coordination becomes the job of the data administrators, by which they maintain a reasonable amount of control over the company's data.

SQL Server Maintenance Plans

Maintenance Plans: • These are sets of scheduled management tasks. SQL Server Maintenance Plan Wizard: • Steps administrator through the process of designing a maintenance plan. Defines tasks. Sets task options. E.g. identifying specific databases. Defines execution schedule.

Efficiency in Job Specialization

Many of the functions involved in the manage- ment of data are highly specialized and require specific expertise. This argues for a full-time staff of specialists who do nothing but manage a company's data and databases.

Database Performance Monitoring

One of the key functions performed by database administration. It is important to know how fast the various applications are executing as part of ensuring that response time requirements are being met.

Passive and Active Data Dictionaries

Passive Data Dictionary: • Used for data documentation purposes, it is a self-contained database. • Data about the entities in the IS environment, and the relationships between entities, are entered into the dictionary. Active Data Dictionary: • Interacts with the IS environment on a real-time basis. • Updates to the dictionary are automatic

Managing Externally Acquired Databases

Some databases are not designed by a company's own personnel but are acquired as part of purchased software packages. • Example: Enterprise Resource Planning (ERP) software.

Data Dictionary Relationships

Table Construction: Which attributes appear in which tables. Security: Which people have access to which databases or tables. Impact of Change: Which programs might be affected by changes to which tables. Physical Residence: Which tables are on which disks. Program Data Requirements: Which programs use which tables. Responsibility: Which people are responsible for updating which databases or tables.

Database Management

The "people side" of database management consists of two major roles: • Data Administration • Database Administration

Data Dictionaries

The IS function has been so busy developing and running systems to support all the other corporate functions that it took a long time before it could invest the resources to develop information systems to support itself. Metadata - data about data. Data dictionary - a database about data. In addition to tracking the basic facts about the represented entities, a data dictionary must keep track of the relationships between the entities

Documentation and Publicity

The data management function is responsible for documenting the data environment. Documentation includes descriptions of data and databases, plus programs, reports, and which people have access to these items. The data management group should perform a publicity function, informing potential users of what data already exist in the databases. Data administrators may help employees discover how to automate more of their work.

Data Dictionary Operations

The database administration group is responsible for the operational aspects, as opposed to the planning aspects, of the data dictionary and any other metadata tools

DBMS Troubleshooting

The database administrators should be the troubleshooting interface. Make an assessment of what went wrong and coordinate the appropriate personnel needed to fix it, including systems programmers, application programmers, and the data administrators themselves.

Uses and Users

The heaviest users of the data dictionary will be IS management and the data administration and database administration functions under them. Systems analysts and program designers can use the data dictionary: • As a source of information about what entities, attributes, and so forth already exist in the IS environment. • As a documentation device for new information.

Database Design

There is a wide range in database adminis- tration responsibilities for database design. In the centralized environment, database administration is responsible for physical database design and possibly logical data-base design. In the decentralized environment, database administration role is usually of a consultant.

DBMS Data and Software Maintenance

These activities include: • Installing new versions of the DBMS. • Installing "fixes" or "patches" to the DBMS. • Performing backup and recovery operations. • Any other tasks related to repairing or upgrad- ing the DBMS or the database.

Data as a Shared Corporate Resource

Virtually all aspects of business have become dependent on their information systems and the data flowing through them. Data, like other corporate resources, requires management. The effective use of its data can give a company a significant competitive advantage. The dedicated departments that manage the company's data are the data administration and database administration departments.