Flashcards
Databases
Cards in this deck (22)
- 1What is the definition of a database?A persistent organised store of data on a computer system
- 2What do databases need to be?-Accurate
-Up to date
-Available to users
-Protected - 3What do administrators protect data against?-Errors
-Loss
-Insufficient Data
-Inconsistencies
-Unauthorized access - 4What can errors cause?-Embarrassment, such as sending bills to those that have died
-Financial loss, such as if a bank account is wrongly credited or debited
-Life or death situations, such as incorrect navigational data for aircraft - 5Meaning of a length check?Must have a certain number of characters or be above or below a certain limit
- 6Meaning of a type check?Must be a certain data type such as character or number
- 7Meaning of a range check?Must fall between certain limits
- 8Meaning of a presence check?Must be filled in
- 9Meaning of a lookup check?Must match what is held on the file
- 10Meaning of a format check?Must conform to a certain pattern
- 11Meaning of a check digit?Must be exactly the same as data previously entered. An algorithm calculates an extra digit which is appended to the data. The same algorithm check data when input.
- 12What is validation?Validation is the process of check data when it is input.
- 13What is verification?Verification is checking that the data entered is correct.
- 14What are the FOUR main things a user needs to do on a database?-Create
-Read
-Update
-Delete - 15What is a flat file database?A database that shows all information and hides none. Laid out in a basic spreadsheet format.
- 16What is a hierarchical database?A hierarchical database is one that assorts its content based on hierarchy. For example a door would come above a hinge which comes above a bolt and nut.
- 17What is a relational database?A relational database is one that stores it's data in tables about entities.
- 18What is an entity?An entity is something in real life which we store data about.
- 19What does DBMS stand for?Database Management Systeem
- 20What does a DBMS do?-Creates database applications
-Protect data
-Run queries to extract data
-Keep data consistent
-Keep data accurate - 21What is the separation of data and applications?*insert picture here*
- 22What are the different data types?-Number
-Number(Currency)
-Text
-Date/Time
-Boolean
Information
- Description
- Flashcards on Databases, created by joshuajenkins10 on 08/05/2015.
- Created by
- joshuajenkins10
- Views
- 1
- Rating