About ORDER BY

forum_thread

ObjectDB Clustering VS Hadoop Hbase

The Hbase is an open source distributed database on Hadoop, it is robust regardless of the performance problem. The ObjectDB cluster may be a distributed database, I guess. But I dont know whether it has only one entry, or each node has an entry. Could you please explain the difference between Hbase and ObjectDB clustering? TIA   ... master-slave cluster, in which WRITE requests are served by one master server and READ requests can be served by all the servers. All the servers in an ObjectDB cluster maintain a full copy ...

 
forum_thread

ObjectDB 2 has been released and is now more affordable

Today, after years of hard work, ObjectDB 2.0 was released and is available for download. In addition, in order to make ObjectDB more affordable, the pricing model was changed:... Avoid overflow of published source code examples by breaking long lines . You may mark in paragraph code words ... names) with the code style (can be applied by ctrl + D). Long stack traces (> 50 lines) and complex ...

 
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;   } ... query = em.createQuery("SELECT t FROM HotTag t ORDER BY t.activity DESC", HotTag.class); I get the exception (in objectdb ...   This can only be resolved by changing private Integer activity; to public ...

 
forum_thread

ClassCastException on SELECT NEW ... after UPDATE over Java RMI

Hi, we are using ObjectDB 2.5.4_04 on Linux. Our application, which uses ObjectDb as a DB, exposes a Java RMI interface which allows remote RMI clients to run JPQL queries on the DB. The application internally runs SELECT NEW ... queries. For example: ... fail with ClassCastException. The same exception is thrown by your DB Explorer tool when trying the same, or similar, SELECT NEW ... ... Caused by: com.objectdb.o.UserException: Failed to build result of type 'NEW ... Caused by: java.lang.IllegalArgumentException: java.lang.ClassCastException@13a7f4bd ...

 
issue

Index Rebuilder

When a new index is added to an existing entity classes that already has instances in the database, it cannot be used in queries, because it starts empty and it is not synchronized with the existing primary data. The Index Rebuilder tool will enable rebuilding indexes, synchronizing their data to the primary data. As a workaround, you can currently use the ObjectDB Doctor to build a new database file, in which such new indexes will be enabled.... in automatic builder of new indexes, which is enabled by default . When using ObjectDB 2.6.6 (or above), ObjectDB automatically activates new indexes by indexing existing entity objects in the background. ...

 
forum_thread

slow performance for a complex query

Hi, We have a query that is constructed dynamically, an example is like this: SELECT DISTINCT $1 FROM CDI $1, Organisation $2, Organisation $3 WHERE ((UPPER($1.cdiId) LIKE 'THREAD14%') AND ((($1.parentOrgId='news') OR (($1.parentOrgId=$2.organisationId) AND ($2.parentOrgId='news'))) OR ((($1.parentOrgId=$3.organisationId) AND ($3.parentOrgId=$2.organisationId)) AND ($2.parentOrgId='news')))) I've also tried running the CDI query first and passing the results into the organisation query as follows: ... subqueries are not supported by ObjectDB. Is there any other way to specify execution order of query ... like this, sometimes JOIN can only be implemented by nested full scan (and indexes cannot help). There are different ... query (if possible in your case) can also be simulated by running a first query and then sending the results of the first query as a ...

 
forum_thread

Version 2.2.7 build 7/8 issue

Hi all, I have problems with builds 7 and 8 when trying to sort entities with mappedBy and my own method in query. This query "SELECT c FROM Customer c order by c.getNormalizedName()" returns List with null objects! With builds 6 and 5 works it correctly. Removing mappedBy from @OneToOne(mappedBy = "address") also helps. My code: ... in query. This query "SELECT c FROM Customer c order by c.getNormalizedName()" returns List with null objects! With builds 6 ... ( "SELECT c FROM Customer c order by c.getNormalizedName()" ) ; List resultList = query. ...

 
api-jdo

javax.jdo.JDONullIdentityException

An instance of this class is thrown when attempting to create an object id when the object id constructor parameter is null.(Exception of JDO)

 
forum_thread

CriteriaBuilder createCriteriaUpdate are not executing

Regards all!! CriteriaBuilder createCriteriaUpdate are not executing. CriteriaUpdate<Order> criteriaUpdate = cb.createCriteriaUpdate(Order.class);   java.lang.UnsupportedOperationException at com.objectdb.jpa.criteria.CriteriaBuilderImpl.createCriteriaUpdate(CriteriaBuilderImpl.java:1502) What is the problem? ... Avoid overflow of published source code examples by breaking long lines . You may mark in paragraph code words ... names) with the code style (can be applied by ctrl + D). Long stack traces (> 50 lines) and complex ...

 
api-jdo

javax.jdo.JDOFatalException

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)