About Cache



Explains how to apply server side bulk update using a JPA/JPQL query. Existing entity objects can be updated, as explained in chapter 2 , by: Retrieving the entity objects into an EntityManager . Updating the relevant entity object fields within an active transaction. ...


How to upgrade from ObjectDB 1.0?

Explains how to upgrade from ObjectDB 1.0 to ObjectDB 2.0.... classpath and the execution classpath). Refresh your IDE cache. Rebuild your project using the new jar file and enhance your classes ...



Pin the parameter instances in the second-level cache.(Method of javax.jdo.datastore.DataStoreCache)


Need to close+open database for a commit to be taken into account

Hi, I have one case where commit (update of entity in this case) is not taken in account unless database is actually closed and re-open, no error. I tried to use flush instead of close+re-open but it does not work. So currently there is a dirty close + open + reload on each update of one of these entities, which is far from ideal. The entity involved contains (between other fields) another entity, that's the only particularity i can see. I tried with and without entity relationship defined, no difference. ... Maybe you should try disabling all sorts of cache in the configuration file, but the information provided is insufficient ...


Database File Compression

ObjectDB database files are usually smaller than database files of other Database Management Systems (object and Relational) but still, an additional internal compression is possible. Usually smaller files are also faster because less I/O operations are required and memory cache can be used more efficiently. But compression and decompression consumes CPU time. Therefore, the effect of compression on Object databases is currently unknown.... faster because less I/O operations are required and memory cache can be used more efficiently. On the other hand, compression and ...


Best File system for objectdb

Hello , whats the best Filesystem do you recommend for speed for objectdb? As far i know these ; btrfs , extfs4 , extfs3 , zfs , ntfs , fat32   Which one do you recommend ?     ... to be small compared to other factors (disk speed, cache size, etc.) ObjectDB Support ObjectDB - ...



Unpin the parameter instance from the second-level cache.(Method of javax.jdo.datastore.DataStoreCache)



Evict the parameter instances from the second-level cache.(Method of javax.jdo.datastore.DataStoreCache)



Refresh the state of the instance from the data store.(Method of javax.jdo.PersistenceManager)


Remove a modified entity cause an optimistic lock exception

Hello, the following examples load and modify an entity, and load and remove the same entity. The first example 'SetAndRemoveIssue.java' is a simple java program which executes without errors. The second example is an OSGi program which fails with an optimistic lock exception. Both examples are equivalent, please execute SetAndRemoveIssue.java (in the OSGi example as a plugin-test). Can you explain the optimistic lock exception? ... lock exception? It seems that the first level cache contains yet a dirty entity although the former query has cause an ...