About availability

forum_thread

Apparent Lazy Loading issues.

Hi, Thanks for the quick investigation. That has indeed fixed that issue. However there appear to be two more. #1 2011-12-19 06:18 Hi, Thanks for the quick investigation. That has indeed fixed that issue. However there appear to be two ...

 
forum_thread

Geospatial functions

Hi, is it possible to implement geospatial functions (e.g. calculating distance between too points given latitude/longitude) ?Normally you would calculate the distance like: #1 2016-01-14 21:02 Hi, is it possible to implement geospatial functions (e.g. calculating distance between too points given ...

 
forum_thread

Pessimestic Locking doesn't release when application unexpectedly terminates.

Hi, We have several services in our app framework that we want to use a cluster singleton. Our approach to this was to use Objectdb's pessimestic locking. This seems to work, but if the owner of the current pessimestic lock abruptly quits without releasing the lock it doesn't get released.    Is there anyway the server can detect that a client (lock owner is no longer connected) and therefore release the lock ?   Thank you   Paul Newman ... note, I did some tests yesterday to calculate resource availability and I'm REALY impressed with the performance and stability of ...

 
manual

JPA Persistence Unit

Explains how to define a JPA persistence unit in the persistence.xml file. A JPA Persistence Unit is a logical grouping of user defined persistable classes (entity classes, embeddable classes and mapped superclasses) with related settings. Defining a persistence unit is optional when using ObjectDB, but required by JPA. ...

 
forum_thread

Lazy Init / Eager / Join Fetch collection strategy ? What to choose ?

Hello, I'm doing some tests to choose the best collection fetch strategy. I have entities with many lazy collections and i don't want to load them all. In JPA / Hibernate world it exist some tests demonstrating how to choose the best strategy. For example : http://zeroturnaround.com/rebellabs/how-to-use-jpa-correctly-to-avoid-complaints-of-a-slow-application/ In this article,join fetch seems to be the right choice. What about ObjectDb ? The implementation is totally different. #1 2015-06-09 21:12 Hello, I'm doing some tests to choose the best collection fetch strategy. I have entities wit ...

 
page

ObjectDB Object Database Features

ObjectDB provides a rich set of features, many of them as the result of supporting the JPA and JDO APIs.... Dynamic composite database connections for high availability and fault tolerance. ...

 
manual

Comparison in JPQL and Criteria API

Explains how comparison operators can be used in JPQL queries, including in comparing null values. Most JPQL queries use at least one comparison operator in their WHERE clause. This page covers the following topics: Comparison Operators Comparing NULL values IS [NOT] NULL Comp ...

 
manual

Logical Operators in JPQL and Criteria API

Explains how to use AND, OR and NOT in JPQL queries. Logical operators in JPQL and in JPA criteria queries enable composition of complex JPQL boolean expressions out of simple JPQL boolean expressions. This page covers the following topics: Logical Operators ...

 
forum_thread

Optimization of Map Queries

hi! I am having loads and loads of occurrences of something like ((com.test.MyEntity) $1.map.get('com.test.MyEntity')).someProperty ... ((com.test.MyEntity) $1.map.get('com.test.MyEntity')).someOtherProperty .. ((com.test.MyEntity) $1.map.get('com.test.MyEntity')).someMoreProperties I need to use full qualified names for casting as well as for the map keys because same entity simple names may occur multiple times. Now I've got two questions: #1 2012-01-18 07:13 hi! I am having loads and loads of occurrences of something like ( ( com . test . ...

 
issue

Navigation through lazy loading from Detached Objects

A main limitation of detached objects (as explained on the Detached Entities manual page) is: Feature Request Version: 2.2.6 Priority: Normal Status: Active Replies: 4 Type:  Feature Request ...