About strong

manual

Entity Management Settings

Explains settings and performance tuning of JPA entities in ObjectDB, the fast Java object database for JPA/JDO.... The valid values are "weak" , "soft " and "strong " . Modified entities are always held by strong references in the persistence context (until commit or flush ), ...

 
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Entity Management Config questions

Hi, the manual states the following regarding config of Entities: http://www.objectdb.com/java/jpa/setting/entities  : <cache ref="weak" level2="0mb" /> The <cache> element specifies settings of the two cache mechanisms for entities:... The valid values are "weak" , "soft " and "strong " . Modified entities are always hold by strong references in the persistence context (until commit or flush ), ...

 
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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.  =(  ) ... softReferenceData in my JdoBlob2 instances, so there is a strong reference to the byte[] when data needs to be written back to ObjectDB ... think is due to ObjectDB datastore page file cache keeping strong references to the pages that comprise the data of the byte[] until the ...

 
issue

Issue with UPPER ?

Hi, Assuming those queries which are all the same except the UPPER calls: ... are all the same except the UPPER calls: < strong > # Case ( 1 ) </ strong > SELECT COUNT ( $1 ) FROM com . lexware . ...

 
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JPQL query to get entities that does not have a child entity in their child entities

I have 2 tables as shown below. Job Table ID JobId Name StartTime    FinishTime    .... 01 001   A  2105:12:10 14:00:00  2105:12:10 14:00:10 02    002  A  2105:12:10 14:00:00  2105:12:10 14:00:00 03    003  A  2105:12:10 14:00:00  2105:12:10 14:00:00 04    004  A  2105:12:10 14:00:00  2105:12:10 14:00:00 And ... I am using following queries. < strong > FINISHED </ strong > Jobs BETWEEN a time interval: @NamedQuery ( name = ...

 
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Caching/Paging Questions...

Greetings ObjectDB team, All below questions assume a very large database (~1,000,000,000 objects): Q1: Two queries with a big overlap between their result sets. If I query the first set and hold the results in memory somehow, would that speed up the execution of the second query since many of its result objects already created and reside in memory ?... reside in memory ? Q2: Do I need to manually use strong references to such cached result objects ? or do ObjectDB exploits ... is not huge). You can either use application managed strong references or you can set the configuration , so strong references ...

 
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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?... is less efficient and has some limitations. For example, strong references to your objects are always used (in order to detect future ... / makeTransientAll ).  ObjectDB doesn't hold strong references to hollow objects, so if your application doesn't ...

 
issue

Super class' field access fails

I have a base class: public abstract class HotObject extends BaseObject {   private Integer activity;   protected HotObject() {     activity = 1;   }   public Integer getActivity() {     return activity;   }   public void setActivity(Integer activity) {     this.activity = activity;   } ... extends BaseObject {   < strong > private Integer activity </ strong >;   protected HotObject ( ) { ...

 
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A lot of ENT and SIV instances which are not cleared by GC

Hello. I have a JSF application (Glassfish 4, Java 8, ObjectDB 2.6.0). In some time the heap is getting 95% full with java.lang.OutOfMemoryError: GC overhead limit exceeded.  The first screenshot from VisualVM shows used heap during a 1000 requests stress test. The second shows that after this test there are many com.objectdb.o.ENT and com.objectdb.o.SIV instances. Why isn't it cleaned? I use simple EJB managers containing EntityManagers. On bean's PreDestroy and in servlet's i make entityManager.clear(); ... ENT object.  entityManager.clear() should release strong references to ENT objects. Are you using enhanced classes? Are ...

 
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NoSuchFieldError: __odbTracker on NetBeans 7.3 + JBoss 7.1.1

When using inheritance throw exception java.lang.NoSuchFieldError: __odbTracker on NetBeans 7.3 + Jboss 7.1.1, but works fine on NetBeans 7.3 + GlassFish 3.1    ... = new City ( ) ; < strong > city. setName ( "Москва" ) ;</ strong > person. setCity ( city ) ; ...