About strong

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 ), ...

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 ), ...

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 . ...

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 ...

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 ...

TYE NullPointerException

I've been seeing the following stack trace in a couple of tests today: ... application uses a collection after it releases the last strong reference to the containing entity object? ... 2.3.2_01. Lazy collections will always hold a strong reference to the containing entity - so this unexpected state would be ...

Navigation through lazy loading from Detached Objects

A main limitation of detached objects (as explained on the Detached Entities manual page) is: ... Just an update to confirm my very strong interest in this feature. We simply can't use our ...

ObjectDB 1.0 Manual

... is not required in order to follow this guide, but a strong background and understanding of the Java language is essential. ...

ObjectDB 2.3 Developer's Guide