3.2.6 - Searching Techniques

Why is efficient searching for data important?

Most data stored by organisations will be in a database format. Some Databases have millions of records.

Interactive systems, such as google or cash machines, rely on data being retrieved from these systems quickly, therefore efficient searching techniques are needs to process all the data quickly and efficiently.

Linear Search

¢Start at the beginning of the list.

¢Compare each item in the list with the search item.

¢Stop when the item is found or when the end of the list is reached.

Advantages.....

¢This technique is very simple to code.

¢A Linear Search works with an unsorted list.

Disadvantage.....

¢Linear Searches are slow, especially with large lists.

Binary Search

1.Find the Middle Item of the Current Search List.

2.Check if the Current Item is the Search Item.

3.If not then make the Current Search List either the Higher Half or the Lower Half of the list.

4.Go to Step 1

Advantage.....

¢Much Faster than a Linear Search, especially as the List increases in size.

Disadvantages.....

¢The List needs to be Sorted.
¢A Binary Search is more Complex to Code.