About Cache

manual

Shared (L2) Entity Cache

Explains how to set and use the EntityManagerFactory's shared cache (L2 / level 2) in JPA 2.... manages. The persistence context serves as a first level cache. An attempt to retrieve an entity object that is already managed by ... . This section describes a level 2  (L2) cache of entity objects, which is managed by the EntityManagerFactory ...

 
forum_thread

Cache usage

after a runtime of several weeks we are now analyzing the usage of the cache and so on. Looking at the heap dump we suspect that the cache is really used (see heap dump attached), the RAM allocated by objectdb is much less than we would expect. The database file has around 25 GByte of size and there is heavy traffic of around 400 clients communicating permanently via webSockets to the objectdb. The config is attached as well. The question is: is the cache really used ? ... of several weeks we are now analyzing the usage of the cache and so on. Looking at the heap dump we suspect that the cache is really used (see heap dump attached), the RAM allocated by objectdb is ...

 
manual

Entity Management Settings

Explains settings and performance tuning of JPA entities in ObjectDB, the fast Java object database for JPA/JDO.... = "true" reflection = "warning" /> <cache ref = "weak" level2 = "0mb" /> <fetch ... The <enhancement> element The <cache> element The <fetch> element The ...

 
manual

Database Management Settings

Explains settings and performance tuning of the ObjectDB Java object database for JPA/JDO.... = "true" /> <processing cache = "64mb" max-threads = "10" synchronized = "false" ... = "true" priority = "40" /> <query-cache results = "32mb" programs = "500" /> ... <index-update> element The <query-cache> element The <extensions> element ...

 
manual

Working with JPA Entity Objects

Explains the entity object lifecycle and the persistence context.... is that the persistence context also functions as a local cache for a given EntityManager . ObjectDB also manages a level 2 shared cache  for the EntityManagerFactory ...

 
forum_thread

In memory processing for ObjectDB

Hi there ! We are building a platform for trades processing where we want to keep our processing speeds very high. We like ObjectDb because its simplicity and the performance benchmarks, but to take it to next level really we wanted to check whether is there any In memory mode available for ObjectDB where recovery is possible, something like prevalyer etc. ... sure if ObjectDB can help us here. Additionally the only cache I see in settings is query cache, is it only that query result sets are cached or I can actually have a ...

 
api-jpa

JPA Miscellaneous

Reference (JavaDoc) of JPA API, including PersistenceUtil, PersistenceUnitUtil, Cache, CacheRetrieveMode, CacheStoreMode, FlushModeType, LockModeType, PessimisticLockScope.... javax.persistence.PersistenceUnitUtil The Cache interface and the CacheRetrieveMode and CacheStoreMode enum ... managing the EntityManagerFactory's shared (level 2) cache: javax.persistence.Cache javax.persistence.CacheRetrieveMode ...

 
api-jpa

javax.persistence.Cache

Interface used to interact with the second-level cache.(Interface of JPA)

 
forum_thread

Soft Reference Object Cache Recommendation

(Trying again.  Last post, ~50 minutes to compose, failed, possibly due to an attachment upload size limit being exceeded before the post attempt.  =(  ) ... to use soft reference for its Level One (L1) object data cache.  I disable the L2 cache and use 1 MB for the ObjectDB Datastore page file cache with page file ...

 
page

ObjectDB Object Database Features

ObjectDB provides a rich set of features, many of them as the result of supporting the JPA and JDO APIs.... L1 entity object cache (per EntityManager). L2 shared entity data cache  (per EntityManagerFactory). ...