How is the organization of indexes for efficient data search implemented?

For efficient data retrieval, indexes are organized as special data structures that allow quick record finding without full scanning.

Commonly used are:

• B-trees and B+-trees — balanced trees providing logarithmic time for search, insert, and delete operations.
• Hash tables — provide fast access by key but do not support ordered search.

In Java, for example, data structures from collections such as TreeMap (red-black tree) for ordered access or HashMap for quick key-based access can be used to implement indexes.

Example of creating an index using TreeMap:

import java.util.TreeMap;

public class IndexExample {
    public static void main(String[] args) {
        TreeMap<Integer, String> index = new TreeMap<>();
        index.put(10, "Record A");
        index.put(20, "Record B");
        index.put(15, "Record C");

        // Fast search by key
        String record = index.get(15); // "Record C"
        System.out.println(record);
    }
}

Thus, indexes significantly speed up data search by structuring and organizing data in special structures.