Entity, collection, and query caching

Opt entities in explicitly

Enabling the global second-level cache does not cache every entity. Add JPA @Cacheable and Hibernate @Cache to selected entities.

@Entity
@Cacheable
@Cache(usage = CacheConcurrencyStrategy.NONSTRICT_READ_WRITE)
class Product(
    @Id @GeneratedValue
    var id: Long? = null,
    var name: String = "",
)

Start with read-heavy reference data. Frequently changing or strict-freshness entities can cost more in invalidation and stale windows than they save.

Collections use separate regions

Caching an entity does not automatically cache its association collections. Annotate the collection itself.

@OneToMany(mappedBy = "department", cascade = [CascadeType.ALL])
@Cache(usage = CacheConcurrencyStrategy.NONSTRICT_READ_WRITE)
val employees: MutableList<Employee> = mutableListOf()

The collection role is normally owner FQCN.property. Use the same role with containsCollection and evictCollectionData. A collection region stores membership while entity state may come from separate entity regions, so inspect both.

Query caching needs two opt-ins

Enable query caching globally and mark each query cacheable.

hibernate.cache.use_query_cache=true
hibernate.generate_statistics=true

val people = session
    .createSelectionQuery(
        "select p from Person p where p.age > :age order by p.id",
        Person::class.java,
    )
    .setParameter("age", 20)
    .setCacheable(true)
    .list()

Query caching stores result identifiers and relies on the update-timestamps region to invalidate results after related tables change. That timestamps region must not expire in Redis.

Rollback and eviction

A new Session after rollback must observe the pre-transaction value. The 1.11.0 suite checks update and delete rollback behavior. Never edit Redis keys directly, because that bypasses Hibernate’s transaction-completion eviction flow.

Sources and tests

• HibernateEntityCacheTest.kt
• HibernateRelationCacheTest.kt
• HibernateElementCollectionCacheTest.kt
• HibernateQueryCacheTest.kt
• HibernateTransactionRollbackTest.kt