Chapter 17 Relational Databases and Normalisation Flashcards
How can data be entered into a database?
- web based forms
- paper forms
- automated devices
- OCR
- OMR
What is the main advantage of having web based forms?
Can have very strong validation for data being entered
What is the main disadvantage of paper forms?
Prone to mistakes, so people are asked to enter data twice
What are some examples of automated devices?
barcode scanners, smart card readers
What does OCR stand for and what is it?
optical character recognition used for handwritten character recognition
What does OMR stand for and what is it?
Optical mark recognition, captures human entered data from forms
What are the names of files that can be used to store captured data? - data that can be in a database
- serial files
- sequential files
- indexed sequential files
- random/direct access files
What is a serial file?
Stores data in entered order, there is no order enforced
What is a sequential file?
stores data in order of the key field, order is enforced
What is a indexed sequential file?
Stores data in order of the key field with an index to allow groups of records to be accessed quickly
What is a random/direct access file?
Data entered is given a unique record number that can be used to access that data
What does DBMS stand for?
database management system
What are some examples of DBMS?
Microsoft Access
Oracle
What is a DBMS?
A software application with many features used for dealing with databases
What are the features of a DBMS?
- creates interface for user
- allows queries
- reports
- additional security
- enforces integrity of data (referential integrity)
- interact with other software applications