# What Is Internal and External Sorting in Data Structure?

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Angela Bailey

What Is Internal and External Sorting in Data Structure?

Data structure is an essential component of computer science that deals with the organization and manipulation of data. Sorting, one of the fundamental operations in data structure, refers to arranging data in a specific order. In this article, we will explore two types of sorting techniques: internal sorting and external sorting.

## Internal Sorting

Internal sorting is a technique used to sort data that can fit entirely in the main memory (RAM) of a computer. It involves rearranging the elements within the memory itself without requiring any additional space.

There are various algorithms for internal sorting, each with its advantages and disadvantages. Some popular internal sorting algorithms include:

• Bubble Sort: This algorithm repeatedly compares adjacent elements and swaps them if they are in the wrong order.
• Insertion Sort: In this algorithm, elements are sequentially inserted into their correct positions in an already sorted portion of the array.
• Merge Sort: Merge sort follows a divide-and-conquer approach by dividing the array into smaller sub-arrays, sorting them individually, and then merging them back together.
• Quick Sort: Quick sort also uses a divide-and-conquer strategy but chooses a pivot element to partition the array into sub-arrays.

## External Sorting

External sorting, on the other hand, is used when dealing with large datasets that cannot fit entirely in main memory. It involves using auxiliary storage such as hard drives or solid-state drives (SSDs) to perform sorting operations effectively.

The main objective of external sorting is to minimize the input/output (I/O) operations required to access the data from the external storage. To achieve this, external sorting algorithms typically employ a combination of internal sorting techniques and efficient disk access strategies.

One widely used algorithm for external sorting is External Merge Sort. It follows a multi-step process that involves dividing the dataset into smaller chunks that can fit in memory, sorting each chunk internally, and finally merging the sorted chunks to obtain the final sorted output.

### Key Differences between Internal and External Sorting

Here are some key differences between internal and external sorting:

• Memory Usage: Internal sorting operates entirely within the main memory, while external sorting utilizes both main memory and external storage.
• Data Size: Internal sorting is suitable for datasets that can fit entirely in memory, whereas external sorting is designed for large datasets that require external storage.
• Efficiency: Internal sorting algorithms optimize memory access patterns, while external sorting algorithms focus on minimizing disk I/O operations.
• Complexity: External sorting tends to be more complex due to the involvement of disk operations and merging of sorted chunks.

In conclusion, internal and external sorting are two distinct techniques used in data structure depending on the size of the dataset and available memory resources. Understanding these concepts is crucial for efficiently managing and manipulating large amounts of data. By employing suitable internal or external sorting algorithms, developers can enhance performance and ensure optimal utilization of system resources.

I hope this article has provided you with a clear understanding of internal and external sorting in data structure!