About change



This class represents exceptions caused by an attempt to update a datastore when the PMF was created as "read-only".(Exception of JDO)


performance limit

Hi, can someone share expirience with performance limits of ObjectDB especialy when quering tables with large records sets. Our issue is with tables with 100.000+ records. Everything was OK when we had few thousand records. We have a simple SELECT statement which selects from a table with 100.000+ records by UserID atribute, tables have from 5 to 20 atributes. Usualy the results range from few hundred to few thousand records. This query takes up to 12 seconds. Is this normal, what when we will have few milion records, how to handle this. ... does ObjectDB uses, is there some default type, can we change it. Last thing we can do is to create a new Database and ...



This class represents user errors that can possibly be retried.(Exception of JDO)



This class represents exceptions that are fatal; that is, the condition that caused it cannot be bypassed even if the operation is retried.(Exception of JDO)


SELECT clause (JPQL / Criteria API)

Explains how to use the SELECT clause and projections in a JPA/JPQL query. The ability to retrieve managed entity objects is a major advantage of JPQL. For example, the following query returns Country objects that become managed by the EntityManager javax.persistence.EntityManager JPA interface Inte ...



This class represents errors in the implementation for which no user error handling is possible.(Exception of JDO)



This class represents exceptions caused by the user accessing an object that does not exist in the datastore.(Exception of JDO)


java.lang.ClassCastException in OSGi runtime when loading data from DB

Hello, I'm trying to use ObjectDB in an OSGi environment (Karaf 4.0.7). I'm now facing ClassCastExceptions on my "entity" classes when I try to read data from the DB. In a very old (2011?) forum entry this problem was already discussed and it appears to be related to classloader problems. My entity is a dedicated bundle. I have one bundle with the database service (doing the actual objectdb actions -> persist, query etc). ... Is there a better way to solve this? Do you by any change have some sample projects for OSGi? I hope I don't have to ...



This class represents exceptions caused by access of an unloaded field while the instance is detached.(Exception of JDO)


composite index not used in query

we defined a composite index for class Action: @Index(name="ssst",members={"startDate","state","subType","type"}) and an index for the OneToMany @OneToMany(fetch=FetchType.LAZY) @Index  public List<ObjectNode> objectsInCharge = new ArrayList<ObjectNode>(); on running a query like ... new examples a composite index is used. Can you change the order of the fields in the composite index: @ Index ...