REAL dbm chapter 1

what does data consist of?

raw facts that are not yet processed to reveal meaning to the end user

information results from...

processing raw data to reveal meaning

information should...

require context, be a bedrock of knowledge, be accurate/relevant/timely

what is the difference between data and information?

data consists of unprocessed facts whereas information is processed data

a database is....

a shared, integrated computer structure that stores data

difference between end-user data and metadata

end-user: raw facts of interest to end user

metadata: where end user data is integrated and managed

the database management system is...

a collection of programs that manages the db structure and controls access to data in the db

the role of the database management system is...

intermediary between the user and the database

advantages of the database management system

enables data to be shared

presents the end user w/ an integrated data view

more efficient data management

improves sharing/security/integrations/access/etc.

types of databases

single-user database (1 user at a time)

multi-user database (multiple users at a time)

the databases by location are...

centralized database (single site)

distributed database (across diff sites)

cloud database (uses cloud data services)

the databases by data type are...

general-purpose database (wide variety in multiple disciplines)

discipline-specific database (focused on specific subjects)

operational database (supports a company's daily operations)

what does an analytical database do?

stores historical data and business metrics used exclusively for tactical/strategic decision making

a data warehouse...

stores data in a format optimized for decision support

online analytical processing (OLAP) is...

tools for retrieving, processing, and modeling

data from the data warehouse

business intelligence...

captures and processes business data to generate information

that supports decision making

databases classified by structure...

unstructured data (exists in its raw state)

structured data (results from formatting)

semistructured data (processed to some exxtent)

extensible markup language (XML)...

represents data elements in textual format

why is database design important?

well-designed db:facilitates data mgmt and generates accurate and valuable information

poorly designed db: causes difficult-to-trace errors that may lead to poor decision making

manual file systems are....

accomplished thru a system of file folders and filing cabinets

computerised file systems...

are a computer-based system created to track data and produce

required reports

file system redux...

modern end-user productivity tools (including spreadsheet programs like excel)

flaws in file system data management include...

lengthy development times

difficulty of getting quick answers

complex system administration

lack of security and limited data sharing

extensive programming

structural dependence vs independence

dependence - access to a file depends on its structure

independence - structure is changed without affecting access to data

data dependence vs independence

dependence - data access changes when storage characteristics change

independence - storage characteristics are changed without affecting accessibility of data

the difference between logical and physical format is...

practical significance of data dependence

storing the same data at different places can lead to

islands of information

increased probability of having different versions of the same data

uncontrolled data redundancy can lead to...

poor data security

data inconsistency

data-entry errors

data integrity problems

the basic components of a database system are....

hardware

software

people

procedures

data

a database system is...

logically related data stored in a single logical data repository

the main functions of a database management system (DBMS) are...

data dictionary management

data storage management

data transformation and presentation

security management

multiuser access control

backup and recovery management

data integrity management

database communication interfaces

disadvantages of database systems

Increased costs

Management complexity

Maintaining currency

Vendor dependence

Frequent upgrade/replacement cycles

a query language...

lets the user specify what must be done without having to specify how

a structured query language (SQL) is...

the de facto query language and data access standard

supported by the majority of DBMS vendors