IS Lab Quiz 1 (M 1-2) Flashcards
It contains SPECIFIC DATA like info about a particular employee or a product
Record
RECORD:
It contains data about ONE ASPECT of the Table subject, such as first name or email address
Field
Each record has a _______. Example being Contoso, Ltd.
Field value
Note
Record: A row like (123, John, Doe, Manager, 70,000) is a complete record for a particular employee.
Field: The columns are fields (Employee ID, First Name, Last Name, Position, Salary).
Field Value: The specific values in the fields, such as John for the field First Name or Manager for the field Position.
It is an organized collection of structured information, or data, typically stored electronically in al computer system.
Database
___ is usually controlled by a database management system (DBMS).
Database
_____ served as the only method of file storage and retrieval before the advent of database management systems
File system data maagement system
What are 4 main limitations of file management system?
Data redundancy
Limited User Access
Lack of Storage and Access Standards
Lack of Transactions
A limitation where multiple users at diff workstations cant access the same (important) data simultaneously
Limited User Access
A type of database that suffer from poor accessibility, redundancy, lack of standard file access and inorganized data
Flat file database
Since flat file databases rely on files that contain record as text without any structural data, they cant relate data from one file to another. This causes ______
data redundancy
Since flat file system relies on files or store data, it necessarily relies on the file system that defines how those files are stored and read. This causes ____
lack of storage and access standards
requesting data from a flat file database simply retrieves data from a single file. requesting and retrieving data from various files at the same time is impossible. This is an example of _____
lack of transactions
____ is defined as a software system that allows the user to define create and maintain the database and provide CONTROL ACCESS to the data. it is a COLLECTION of programs used for MANAGING data and simultaneously supports differnt types of user to create manage retrieve update and store info.
Database Management System
What are the 9 advantages of DBMS
– redundancy problem can be solved
– high security level
– Presence of Data Integrity
– Support Multiple users
– Avoidance of inconsistency
– Shared Data
– Enforcement of Standards
– Restricted unauthorized accesss
– provide backup of data
What are 3 main levels of data abstraction?
– Physical or Internal Level
– Logical or Conceptual Level
– View or External Level
ARRANGEMENT BEING:
VIEW LEVEL
LOGICAL LEVEL
PHYSICAL LEVEL
one of the 3 main levels of DBMS
It tells us how the data is actually stored in memory. Usability, size of memory, and the number of times records are factors that we need to know while designing the database.
Physical or Internal Level
AKA lowest level of data abstraction
one of the 3 main levels of DBMS
This level comprises the info that is actually stored in the database in the form of tables. it also stores the relationship among data entities in relatively simple structures.
The info available to the user a the view level is unknown.
Logical or conceptual level
one of the 3 main levels of DBMS
it describes the entire database in terms of a small number of relatively simple structures. it may involve complex physical level structures but users at this level does not need to be aware of this complexity.
Logical or Conceptual level
logical level may involve complex physical level structures but users at this level does not need to be aware of this complexity. this is referred to as ___
physical data independence
one of the 3 main levels of DBMS
Only a part of the actual database is viewed by the users. this level exists to ease the accessibility of the database by an individual user. users view data i nthe form of rows and columns. tables and relations are used to store data. users can view and interact with the database, but storage and implementation details are hidden from them.
View or External level
aka HIghest level of abstraction
________ = will contain block of storages (GB, TB)
________ = will contain the fields and the attributes of data
________ = works with CLI or GUI access of database
- physical
- logical
- view
_____ is mainly defined as a propert of DBMS that helps you to change the data base schema at one level of a system without requiring changing the schema at the next level.
Data indepdendence
_____ helps to keep the data separated from al programs that makes use of it.
Data independence
2 levels of abstraction under data independence are?
1 Physical level data indep
2.Logical level data indep