Fixed Length Vs. Variable Length

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Fixed Length
A file where each records is of the same length because it contains the same number of bytes in each record, for example a postcode will always have 7 characters.
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Some fields may need to be "padded" out so they are the correct length, e.g. People's surnames. Padding out simply involves putting spaces after the last characater, is order for the field to be of the same length as others.
One advantage is that the access is fast because the computer knows where each record starts and finishes, therefore the processing of all data (read/write) will be fast.
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A disadvantage of this is that records are usually larger; therefore need more storage space and are slower to transfer (load or save) or transmit down a network.
Another advantage is that records are easier to program as they can be calculated know how much space will be required
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Variable Length
This type of record has different number of bytes in each record or different number of fields
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a disadvantage of this is that it makes it difficult to calculate how much space will be required
Another disadvantage of this record is that records are slower to process (read/write) by computer as start and end locations have to be calculated at read/write time
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This type of record saves storage space as no blank space
Another advantage is that files will be faster to transmit down a network
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Other cards in this set

Card 2

Front

Some fields may need to be "padded" out so they are the correct length, e.g. People's surnames. Padding out simply involves putting spaces after the last characater, is order for the field to be of the same length as others.

Back

One advantage is that the access is fast because the computer knows where each record starts and finishes, therefore the processing of all data (read/write) will be fast.

Card 3

Front

A disadvantage of this is that records are usually larger; therefore need more storage space and are slower to transfer (load or save) or transmit down a network.

Back

Preview of the front of card 3

Card 4

Front

Variable Length

Back

Preview of the front of card 4

Card 5

Front

a disadvantage of this is that it makes it difficult to calculate how much space will be required

Back

Preview of the front of card 5
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