What types of data structures would you use to ensure the fastest possible information retrieval?

For the fastest information retrieval, data structures with quick access by key are usually used:

• Hash tables (dict in Python): provide an average search time of O(1), suitable for quick access by a unique key.
• Sets: for fast membership testing.
• Trees (e.g., balanced trees): if ordered search or range queries are needed.

Example of using dict for quick search:

users = {
    'alice': {'age': 30},
    'bob': {'age': 25}
}

# Quick search by name
user = users.get('alice')
if user:
    print(user['age'])  # 30