Chap 1 (Databases and Database Users) Flashcards
What are the two types of database
Numeric
Textual
A collection of related data.
Database
Known facts that can be recorded and have an implicit meaning
Data
Some part of the real world about which data is stored in a database. For example, student grades and transcripts at a university.
Mini-world
A software package/ system to facilitate the creation and maintenance of a computerized database
Database Management System (DBMS)
The DBMS software together with the data itself. Sometimes, the applications are also included.
Database System:
In the database system environment, application programs/queries are part of?
Database System
In the database system environment, software to process queries/programs and software to access stored data are part of?
DBMS Software
After the DBMS Software Process in the database system environment, where does stored database definition (meta-data_ and stored database belong to?
Database System
What are the 4 DBMS Functionalities?
Define
Construct
Manipulate - Retrieval, Modification, Accessing
Processing and Sharing
What are the application activities against a database?
Queries and Transactions
Access different parts of data and formulate the result of a request
Queries
may read some data and “update” certain values or generate new data and store that in the database
Transaction
stores the description of a particular database (e.g. data structures, types, and constraints)
DBMS catalog
the description of a particular database (e.g. data structures, types, and constraints)
meta-data
Insulation between programs and data
Program-data interdependence
Allows changing data structures and storage organization without having to change the DBMS access programs
program-data independence.
3 Main Characteristics of the Database Approach
Data Abstraction
Support multiple views of data
Sharing of data and multi-user transaction processing
In _____, A data model is used to hide storage details and present the users with a conceptual view of the database.
Data Abstraction
In Data Abstraction, programs refer to the _________ rather than data storage details
data model constructs
Each user may see a different view of the database, which describes only the data of interest to that user
multiple views of the data
Allowing a set of concurrent users to retrieve from and to update the database
Sharing of data and multi-user transaction processing
_________ within the DBMS guarantees that each transaction is correctly executed or aborted
Concurrency control
__________ ensures each completed transaction has its effect permanently recorded in the database
Recovery subsystem
_________ is a major part of database applications. This allows hundreds of concurrent transactions to execute per second.
OLTP (Online Transaction Processing)
Database Users may be divided into?
Actors on the scene
Workers behind the scene
Types of actors on the scene
Database administrators
Database Designers
End-users
System Analysts and Application Developers
Responsible for authorizing access to the database, for coordinating and monitoring its use, acquiring software and hardware resources, controlling its use and monitoring efficiency of operations.
Database administrators
Responsible to define the content, the structure, the constraints, and functions or transactions against the database. They must communicate with the end-users and understand their needs.
Database designers
They use the data for queries, reports and some of them update the database content.
End-users
Types of end-users
Casual
Naive/Parametric
Sophisticated
Stand-alone
access database occasionally when needed
Casual end-user
they make up a large section of the end-user population.
Naive or Parametric
Many use tools in the form of software packages that work closely with the stored database.
Sophisticated end-user
Mostly maintain personal databases using ready-to-use packaged applications.
Stand-alone end-user
This category currently accounts for a very large proportion of the IT work force.
System Analysts and Application Developers
They understand the user requirements of naïve and sophisticated users and design applications including canned transactions to meet those requirements
System Analysts
Implement the specifications developed by analysts and test and debug them before deployment.
Application Programmers
There is an increasing need for such people who can analyze vast amounts of business data and real-time data (“Big Data”) for better decision making related to planning, advertising, marketing etc.
Business Analysts
Types of Actors Behind the Scene
System Designers and Implementors
Tool Developers
Operators and Maintenance Personnel
Design and implement DBMS packages in the form of modules and interfaces and test and debug them. The DBMS must interface with applications, language compilers, operating system components, etc.
System Designers and Implementors
Design and implement software systems called tools for modeling and designing databases, performance monitoring, prototyping, test data generation, user interface creation, simulation etc. that facilitate building of applications and allow using database effectively
Tool Developers
They manage the actual running and maintenance of the database system hardware and software environment.
Operators and Maintenance Personnel
refer to data item names, display formats, screens, report structures, meta-data (description of data), Web page layouts, etc.
Standards
The Hierarchical and Network Models were introduced in mid 1960s and dominated during the seventies
Early Database applications
_______ was originally introduced in 1970, was heavily researched and experimented within IBM Research and several universities.
Relational Model
________ were introduced in late 1980s and early 1990s to cater to the need of complex data processing in C A D and other applications.
Object-Oriented Database Management Systems (OODBMS)
Many relational D B M S s have incorporated object database concepts, leading to a new category called ______
object-relational DBMSs (ORDBMSs)
____________ add further capabilities (e.g. for multimedia data, text, X M L, and other data types)
Extended relational systems
When is a DBMS not necessary?
If database are simple and not expected to change
Access to data by multiple not required
When is DBMS may be infeasible
may not fit in available storage in embedded systems
When no DBMS may suffive
if there are stringent real-time requirements
Not able to handle complex data because of modeling limitations
If special operations needed that isnt supported
