External data structures are stored in: A. Objects B. Sequential Files C. Array D. Linked Lists
The correct answer and explanation is:
Correct Answer: B. Sequential Files
External data structures are stored in sequential files because these files provide an efficient way to handle large volumes of data stored outside the main memory. Unlike arrays or linked lists, which are typically internal data structures stored in a computer’s RAM during runtime, sequential files reside on external storage media such as hard drives or SSDs.
A sequential file organizes data in a specific, linear order, usually based on a key field. When data is stored in this format, it can be read from beginning to end in the order it was written. This is especially useful for applications like transaction logs, backups, and simple databases where data is primarily processed in a sequential manner.
Sequential file storage is also advantageous for batch processing. When data does not need to be frequently updated in real time, and access patterns are predictable, sequential files offer simplicity and efficiency. Reading and writing large blocks of data sequentially from disk is generally faster than accessing scattered pieces of data randomly.
On the other hand, arrays and linked lists are dynamic memory structures used while a program is running. Arrays store elements in contiguous memory locations, and linked lists consist of nodes linked using pointers. Both are efficient for in-memory operations but are not suited for direct external storage. Objects, which encapsulate data and behavior, can be serialized and stored externally, but they are not themselves external storage structures.
In conclusion, when data needs to be stored externally and processed in an organized and linear fashion, sequential files are a practical and effective solution. Their straightforward layout makes them ideal for storing external data structures that need to be accessed or processed in sequence.