How does indexing improve database interactions?

Indexing improves database interactions by speeding up data retrieval operations and enhancing overall database performance.

In more detail, indexing is a data structure technique to efficiently retrieve records from the database files based on some attributes on which the indexing has been done. Indexing in databases is similar to what we see in books. Books have an index where different topics are arranged in alphabetical order, and the page number they are found on is listed. In the same way, indexing in databases allows the database management system (DBMS) to find and retrieve data faster.

Indexes are used to quickly locate data without having to search every row in a database table every time a database table is accessed. They can be created using one or more columns of a database table, providing the basis for both rapid random lookups and efficient access of ordered records. An index can be used to efficiently find all rows matching some column in your query and then walk through only that subset of the table to find exact matches. If you don't have indexes on any column in the WHERE clause, the SQL server has to go through all the rows in the table to find matches, which can be very slow if your table is big.

Moreover, indexing also improves the performance of queries using joins by enabling faster identification of records to be joined. It also allows sorting and grouping operations to be performed more efficiently.

However, it's important to note that while indexes significantly improve read operations, they can slow down write operations like insertions, deletions and updates, as the index also needs to be updated. Therefore, it's crucial to maintain a balance and only use indexing for columns that will be frequently searched or sorted.

In conclusion, indexing is a powerful tool that, when used correctly, can greatly enhance the speed and efficiency of database interactions. It's a fundamental concept that every computer science student should understand and utilise effectively.