The N+1 query problem

An ORM hides the SQL from you, and the classic cost is the N+1 problem. You load 50 orders with one query. Then you fetch each order's customer inside a loop.

You have now run 51 queries where one or two would do. At 5 ms each, that is a quarter of a second of waiting. In Prisma, fetch the related data up front with include or select.

In Drizzle, use its relational queries with the with option, or write a join. In GraphQL resolvers, a DataLoader collects the per-item lookups into one batch. Turn on query logging in development, such as Prisma's log option, and count the queries per request.