About comparison

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EntityManager JPA or JDO impl and different behavior

Hi, I have an issue with the EntityManager. My persistance XML looks like: <?xml version="1.0" encoding="UTF-8"?> <persistence version="2.0" xmlns="http://java.sun.com/xml/ns/persistence" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://java.sun.com/xml/ns/persistence http://java.sun.com/xml/ns/persistence/persistence_2_0.xsd"> ... method use more than the database id for generation or comparison, it all fails horribly. Have a look at the output from the second ...

 
forum_thread

Pre-detach loading: retrieval by navigation not working in if statement

objectdb-2.6.3_04 JDK1.7 VM option at runtime: -javaagent:lib/objectdb.jar Experimental mode: objectdb.temp.no-detach NOT USED ... If so, in order to perform a truly scientifically clean comparison, I might be able to fine-tune my Ant script to detect @Entity and ...

 
forum_thread

evictAll() behavior

I'm writing a multi-user drawing tool, using objectdb as the central store.  When a user press F5, I want to pick up all the changes from the database.  So, I call evictAll() in the following ways: pmf.getDataStoreCache().evictAll();  // the factory pm.evictAll();                                 // the persistence manager A couple of questions about this: 1. the first evictAll() seems to be clearing the L2 cache -- is this correct 2. the evicts only work when they are done inside a transaction -- is this specified in the JDO spec?... to objects to detect changes on commit by snapshot comparison).   ObjectDB Support ...

 
manual

[ODB1] Chapter 4 - JDO Metadata

Shows how to define JDO metadata for persistence capable classes.... in the indexed field. Both equality ( == , != ) and comparison ( < , <= , > , >= ) queries are supported by ...

 
forum_thread

Performance in large transactions

Hello, we have a performance problem when we use a large transaction. Let's do exactly the same in several transactions the ObjectDB works much faster. In our use case, we create many new entities and between the creations we call a select query. The execution of the query becomes slower at each iteration. (In the query, we search for an item of type Entity2. However, there is only one entity.)   Pseudocode for the fast and the slow solution FAST: ... in the persistence context are untrackable and requires comparison on every flush. To avoid this, we introduce now a new ...

 
manual

Index Definition

Describes how to define indexes in JPA entity classes and explains how indexes are used in JPQL queries.... to access the entities themselves. Instead, because of the comparison in the WHERE clause, a full index scan would be performed. ...