<p>The "N+1 selects problem" is generally stated as a problem in Object-Relational mapping (ORM) discussions, and I understand that it has something to do with having to make a lot of database queries for something that seems simple in the object world.</p>

<p>Does anybody have a more detailed explanation of the problem?</p>

Suppose you have COMPANY and EMPLOYEE. COMPANY has many EMPLOYEES (i.e. EMPLOYEE has a field COMPANY_ID).
In some O/R configurations, when you have a mapped Company object and go to access its Employee objects, the O/R tool will do one select for every employee, wheras if you were just doing things in straight SQL, you could
```
select * from employees where company_id = XX
```
.  Thus N (# of employees) plus 1 (company)
This is how the initial versions of EJB Entity Beans worked.  I believe things like Hibernate have done away with this, but I'm not too sure.  Most tools usually include info as to their strategy for mapping.