Long-lived sessions with several large objects will take more memory and can cause out-of-memory errors in your web application. What is Second-Level Cache in Hibernate? Now, let's come to the second-level cache.
This is an optional Cache that Hibernate provides. Unlike the first-level cache which is accessible only to the session that maintains it, Second-level Cache is accessible to all Sessions. The next session will get the data from the Second-level Cache. The Second Level cache is by default disabled. Hibernate also doesn't provide any caching implementation for that. You also need to define Concurrency Strategy to be used along with Second level cache, like Transactions, read-write, nonstrict-read-write, or read-only.
Ask Question. Asked 11 years, 6 months ago. Active 4 years, 6 months ago. Viewed 8k times. Improve this question. Pascal Thivent k gold badges silver badges bronze badges. Add a comment. Active Oldest Votes. Hibernate comes with three different caches: first level, second level and query cache. The query cache is used to cache queries and their parameters and their results. Improve this answer.
This attribute is optional, and defaults to the fully-qualified class name of the class, or the qually-qualified role name of the collection. Whether or not to include all properties.. Optional, and can take one of two possible values. A value of all includes all properties. This is the default. A value of non-lazy only includes non-lazy properties. Just as in the Example 6. There are some specific differences in the syntax for the attributes in a mapping file. The caching strategy.
This attribute is required, and can be any of the following values. The name of the second-level cache region. This optional attribute defaults to the class or collection role name. Defaults to all and can also be non-lazy. A read-only cache is good for data that needs to be read often but not modified. It is simple, performs well, and is safe to use in a clustered environment. Some applications only rarely need to modify data. This is the case if two transactions are unlikely to try to update the same item simultaneously.
In this case, you do not need strict transaction isolation, and a nonstrict-read-write cache might be appropriate. If the cache is used in a JTA environment, you must specify hibernate. In other environments, ensore that the transaction is complete before you call Session. A read-write cache is appropriate for an application which needs to update data regularly.
Do not use a read-write strategy if you need serializable transaction isolation. In non-JTA environments, be sure the transaction is complete before you call Session. To use the read-write strategy in a clustered environment, the underlying cache implementation must support locking. The build-in cache providers do not support locking. The transactional cache strategy provides support for transactional cache providers such as JBoss TreeCache. You can only use such a cache in a JTA environment, and you must first specify hibernate.
Syncing or removing a cached item. The state of an object is synchronized with the database when you call method flush. Leave a Reply Cancel reply Your email address will not be published. Find Article Search. Video Course. Hypersistence Optimizer. ERP Contact. By continuing to use this website, you agree to their use.
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