HuZeJi/nplusoneproblem.md

## nplusoneproblem.md

      
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              nplusoneproblem.md
            
          
Solution
Description
When to Use


JOIN FETCH
Explicitly fetches associated entities in the same query as the parent (JPQL/HQL).
When a specific query needs eagerly fetched associations that are otherwise lazy.


Batch Fetching
Loads lazy associations in batches (@BatchSize annotation). Reduces N queries to N/batch_size queries.
General optimization for lazily loaded collections accessed frequently after initial parent fetch.


Entity Graphs
Defines a graph of objects to be fetched for a specific query, overriding default or entity-level fetching.
Complex scenarios requiring fine-grained control over fetching for specific use cases.


Eager Fetching
Configures an association to always be loaded with the parent entity (FetchType.EAGER).
Cautiously, only when the associated data is always needed with the parent and the performance impact is acceptable.
Solution	Description	When to Use
`JOIN FETCH`	Explicitly fetches associated entities in the same query as the parent (JPQL/HQL).	When a specific query needs eagerly fetched associations that are otherwise lazy.
Batch Fetching	Loads lazy associations in batches (`@BatchSize` annotation). Reduces N queries to N/batch_size queries.	General optimization for lazily loaded collections accessed frequently after initial parent fetch.
Entity Graphs	Defines a graph of objects to be fetched for a specific query, overriding default or entity-level fetching.	Complex scenarios requiring fine-grained control over fetching for specific use cases.
Eager Fetching	Configures an association to always be loaded with the parent entity (`FetchType.EAGER`).	Cautiously, only when the associated data is always needed with the parent and the performance impact is acceptable.