ICT databases
- Created by: buneme
- Created on: 20-04-15 13:43
View mindmap
- Databases
- Encoding data
- Drawbacks
- One letter codes can be confusing
- Advantages
- Faster to type in
- More data can be displayed on screen
- File size is smaller
- Drawbacks
- Manipulating data
- Creating a report
- Formatted output from a database
- Updating
- Deleting
- Searching
- Also known as querying
- Descending order
- Sorting
- Creating a report
- Structure
- Field: A column in the database
- Record: A row in the database
- File: A collection of related records
- Data types
- Text: Used for telephone numbers and text
- Number: Integers & real numbers
- Date/Time
- Boolean - for yes or no answers
- Autonumber - Often the key field to make each record unique
- Currency - For numbers with a £ sign
- General benifits and drawbacks
- Benefits
- Data can be edited more easily
- Data is easier to back up
- Data is easily shared
- Data is easily transferred using networks
- Drawbacks
- Computers can be hacked leading to loss of data
- Data can be copied quickly so personal data may be stolen
- Loss of data due to power cut and hardware failure
- Training needed to enable staff to access data
- Benefits
- Validation
- Data type check - Data has tyo be of a specific named type
- Drop down list - restricts the user to a specific list of possible data
- Format check - Data has to conform to the combination of charecters
- Range check - Where a min & max values are set up
- Definition - A rule set up to ensure that data entered is sensible
- Length check - ensures exactly x charrecters are entered
- Check digit - A number added at the end of a block of numbers, used to check that the numbers have been entered correctly
- Batch - adds up meaningful data
- Hash - Adds up meaningless data
- Presence check - Data has to be entered into a field
- Verification
- Definition - Ensures that data sent is the same as the data sent is the same as the data recieved when data is transmitted between computers
- Double entry - Checks if the same data, entered twice, matches
- Visual check - When a user carefully reads what has been entered in and compares it with the original data source
- Parity check - checks the data has been entered correctly compared to the source
- Security issues
- Password protection - stops unauthorized access
- Password protocol - changing passwords regularly
- Access rights - read only
- Encryption - makes intercepted data unreadable
- Saved off site - saved in a fire proof safe
- Antivirus - prevents malicious progeams from damaging data
- Physical security - lock doors
- Firewall - prevents data been accessed by hackers
- Encoding data
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