03_09 Database Design Flashcards
A design philosophy that begins by identifying individual design components and then aggregates them into larger units.
In database design, the process begins by defining attributes and then groups them into entities.
bottom-up design
The external limits to which any proposed system is subjected.
These limits include budgets, personnel, and existing hardware and software.
boundaries
A process by which all database design decisions are carried out centrally by a small group of people.
Suitable in a top-down design approach when the problem domain is relatively small, as in a single unit or department in an organization.
centralized design
A storage technique that stores related rows from two related tables in adjacent data blocks on disk.
clustered table
The strength of the relationships between a module’s components.
cohesivity
Module cohesivity must be high.
Tools used to automate part or all of the SDLC.
computer-aided systems engineering (CASE)
A process that uses data-modeling techniques to create a model of a database structure that represents real-world objects as realistically as possible.
The design is both software- and hardware-independent.
conceptual design
The process of database design and implementation.
database development
A subset of a distributed database.
database fragment
Although the fragments may be stored at different sites within a computer network, the set of all fragments is treated as a single database. See also horizontal fragmentation and vertical fragmentation
A cycle that traces the history of a database within an information system.
The cycle is divided into six phases: initial study, design, implementation and loading, testing and evaluation, operation and maintenence, and evolution.
Database Life Cycle (DBLC)
A set of database privileges that could be assigned as a unit to a user or group.
database role
A process in which conceptual design models subsets of an organization’s database requirements, which are then aggregated into a complete design.
Such modular designs are typical of complex systems with a relatively large number of objects and procedures.
decentralized design
A document that provides a precise, detailed, up-to-date, and thoroughly reviewed description of the activities that define an organization’s operating environment.
description of operations
A level of database backup in which only the last modifications to the database are copied.
differential backup
A complete copy of an entire database saved and periodically updated in a separate memory location.
full backup (database dump)
A full backup ensures a full recovery of all data after a physial disaster or database integrity failure.
A system that provides for data collection, storage, and retrieval.
It facilitates the transformation of data into information and manages both data and information.
information system (IS)
An IS is composed of hardware, the DBMS and other software, data-base(s), people, and procedures.
A stage in the design phase that matches the conceptual design to the requirements of the selected DBMS and is therefore software dependent.
logical design
Logical design is used to translate the conceptual design into the internal model for a selected DBMS.
All data elements required by database transactions must be defined in the model, and all data elements defined in the model must be used by at least one database transaction.
All that is needed is there, and all that is there is needed.
minimal data rule
A design segment that can be implemented as an autonomous unit and is sometimes linked to produce a system.
module
An IS component that handles a specific function.
module
The extent to which modules are independent of one another.
module coupling
A stage of database design that maps the data storage and access characteristics of a database.
physical design
Because these characteristics are a function of the types of devices supported by the hardware, the data access methods supported by the system physical design are both hardware- and software-dependent. See also physical model
The part of a system that defines the extent of the design, according to operational requirements.
scope
The process that establishes the need for an IS and its extent.
systems analysis
The cycle that traces the history of an IS.
Systems Development Life Cycle (SDLC)
The SDLC provides the big picture within which database design and application development can be mapped out and evaluated.
The process of creating an IS.
systems development
A design philosophy that begins by defining the main structures of a system and then moves to define the smaller units within those structures.
In database design, this process first identifies entities and then defines the attributes within the entities.
top-down design
A backup of only the transaction log operations that are not reflected in a previous backup copy of the database.
transaction log backup
A technique that creates logical representations of computing resources that are independent of the underlying physical computing resources.
virtualization
