Identifying and Fixing N+1 Queries and Missing Join Optimizations

The N+1 query pattern is one of the most common and costly performance problems in database-backed applications. It happens when code fetches a list of N rows and then executes one additional query per row — resulting in N+1 round trips to the database. A list of 1,000 orders becomes 1,001 queries. This lesson shows you how to spot N+1s in the query log and rewrite them as efficient single queries.