Hibernate / Hibernate interview questions
Explain N+1 SELECT problem in Hibernate.
Hibernate ends up executing N+1 SQL queries to populate a collection of N elements referred as N+1 SELECT problem that occurs due to N+1 lazy loading and load on demand fetching strategy.
Let's say you have a collection of company objects (database rows), and each company has a collection of employee objects (database rows). In other words, company:employee is a 1-to-many relationship. If you need to iterate through all the companies, and for each one, print out a list of the employees, you have to perform one select to get all companies, and then N additional selects to find the list of employees, where N is the total number of companies.
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