Dear Andrew, @andatki
I found the explanation regarding the use of .includes()
with a limit
in the context of vehicle reservations to be quite insightful. However, I believe the discussion on performance implications could benefit from further clarification, particularly regarding the difference in behavior with and without a limit
.
Here’s a suggested rewrite to enhance clarity:
When using .includes()
to load vehicle reservations, the query is split into two parts. First, a query retrieves a limited number of vehicles (e.g., 2 vehicles). Then, another query fetches the associated reservations for these vehicles using an IN
clause with the vehicle_id
s of the retrieved vehicles. Keep in mind that if the IN
clause contains too many values, it can lead to performance issues.
Performance Implications
- Without limit: If there are many vehicles, the
IN
clause can become very large, which may degrade performance. - With limit: The
IN
clause remains small, improving performance for the secondary query.
Additionally, this explanation can move before LEFT OUTER JOIN
part, in order to avoid a context switch.
I hope this suggestion helps make the performance implications clearer for the readers.
Best regards,
Viktor