Faster Rails: Is Your Database Properly Indexed?

As web applications grow in user base and data volume, they often experience performance issues, primarily due to inefficient database queries, such as N+1 queries and lack of proper indexing. The article emphasizes the importance of implementing database indexes to enhance query performance, particularly for columns frequently used in WHERE, HAVING, and ORDER BY clauses, as well as for unique lookups and foreign keys. Indexes work similarly to a book's index, allowing for quicker data retrieval by referencing a sorted list, thus avoiding full table scans. However, the use of indexes should be carefully considered, as they can sometimes lead to increased storage requirements or even slow down applications under certain conditions. The article also briefly mentions Semaphore’s commitment to optimizing continuous integration processes with features like Semaphore Boosters, which parallelize test suites to reduce runtime.