Eager loading
Eager loading is a data-loading strategy that retrieves required data before it is requested individually, often fetching related data together with its primary entity.
Java Persistence with Spring Data and Hibernate epub
Eager loading is a persistence technique that retrieves associated data together with the owning entity rather than deferring access.
- How it is used
- Keeps required associations available after detachment and helps tailor entity loading to a procedure’s data needs.
- How deep it goes
- Works through mappings, JOIN and SELECT execution, detached-state boundaries, and performance tradeoffs; does not develop SQL result-set mapping.
- Examples
- Uses an item with a seller and bids, showing eager mappings, generated SQL, detachment checks, and multiple-SELECT fetching.
- What you can do after
- Operate/configure it with JPA fetch mappings and Hibernate fetch strategies, choosing procedure-specific loading while checking query count and result size.
Read how Java Persistence with Spring Data and Hibernate epub explains eager loading →
.NET in Action, Second Edition
Eager loading retrieves an entity and specified related entities as part of the same query operation.
- How it is used
- Retrieves related entities alongside primary entities when a query needs the complete object graph immediately.
- How deep it goes
- Explains Include, multiple relationships, and query trade-offs, but defers explicit and select loading.
- Examples
- Demonstrates loading Books with Ratings and printing each rating’s stars and comment.
- What you can do after
- Apply it via Entity Framework Core by adding Include expressions to relationship queries.
Read how .NET in Action, Second Edition explains eager loading →
Related concepts
- lazy initializationcontrasts with · Lazy initialization is a technique that postpones creating, retrieving, computing, or loading a value or resource until it is needed.
- FetchType.EAGERconfigured by · FetchType.EAGER is a Jakarta Persistence fetch option specifying that an associated value is retrieved with its owning entity.
- N + 1 query problemaddresses · The N+1 query problem is an inefficient data-access pattern in which an initial query retrieves a collection and a separate additional query retrieves related data for each item.
- Cartesian productcontrasts with · A Cartesian product is the set of all ordered tuples formed by selecting one element from each of multiple sets or sequences.
- fetch profileconfigured by · A fetch profile is a Hibernate-defined loading configuration that selectively overrides association and collection fetching for a unit of work.
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