In what cases does HashMap data structure show better search speed compared to B-tree?

HashMap shows the best performance in search speed for exact keys in cases where:

• Keys are well distributed, minimizing collisions.
• The data size allows the entire structure to be stored in memory, ensuring quick access.
• Ordered traversal of elements is not required.

HashMap provides amortized O(1) access time for key lookup, whereas B-tree has a search time of O(log n). However, B-tree is efficient when working with large volumes of data on disk and supports ordered access.

Example:

If you have a large number of unique keys and need to quickly retrieve a value by an exact key without the need for sorting, HashMap would be preferable.