CH.5- Data base systems, data centers, business intelligence Flashcards
Database
- Database: organized collection of data.
- Helps organization achieve its goals.
Database Management Systems (DBMS)
-Database management systems (DBMS):
- group of programs that manipulate database
- interface between the database –>users–>programs
Database administrator (DBA)
- skilled IS professional
- directs all activities related to database.—-> a person
- Like a security guard
Character
basic building block of most information, consisting of : ○ upper case letters, ○ lower case letters, ○ numeric digits, ○ special symbols
Characters put together = field
Field
-Collection of characters with meaning.
○ a name, number or combination of characters
Record
-collection of related data fields all related to one object, activity, individual.
File
-Collection of related records.
I.e employee file is a collection of all company employee records
Hierarchy of data
(at bottom) bits => characters => fields =>records,
=>files, => databases (at top)
Entity
Grouping similar items.
○ general class of ppl, places, things for which data collected, stored, maintained.
○ i.e employees, investory, customers
Attribute
• Attribute: Characteristic of an entity.
○ Employee 1st name, last name, hire date,department number are attributes for an employee
Data Item
specific value of an attribute
Key
field or set of fields in a record used to identify the record
Primary Key
field or set of fields that uniquely identifies the record (I.e an item number)
• No other record can have the same primary key
Traditional approach to data mgmt
Database approach to data mgmt
traditional: used data files dedicated to that system
Database approach: pool of related data shared by variety of information systems
Data Centre
- Traditional
- Modular
climate controlled building/set of bldgs that keep database servers and systems
- Traditional- rows
- Modular- shipping Containers