About performance

forum_thread

No clue how to query with collection

Hi there! Actually, what I have is something like: @Embedable class Address { String getStreet(); int getStreetNo(); } @Entity class Contact { Collection<Address> getAddresses(); }   ... Contact just for ordering. It might also improve performance. ObjectDB Support ObjectDB - Fast ...

 
forum_thread

using objectdb.jar in writing data to mariadb or mysql db

Hello All, ... etc. as an alternative to using ObjectDB (although performance may be slower than using ObjectDB). ObjectDB is reliable in ...

 
forum_thread

Index on map key

Is there a way to create an Index with @Index on the key of a map? ... example with and without the index definition shows that performance with index is better. ObjectDB Support ...

 
issue

[ObjectDB 2.2.6_02] Unexpected exception (Error 990) at com.objectdb.o.OBC.aJ(OBC.java:961)

I was experiencing an exception so I did a test to reproduce it.   here it is. Bug Version: Priority: Normal Status: Fixed Replies: 1 Type:  Bug ...

 
forum_thread

Some details about db behavior

Suppose I have two entities... A B -> A B has a ManyToOne relationship with A. When my database is empty and I persist a valid B entity (that contains actual A reference) I observe some behaviour that I'm not sure I understand. ... as this might be critical for the application and performance. If there are any other materials (books articles) that ...

 
forum_thread

OptimisticLockException

Have read read the documentation on optimistic locks, still not sure how to deal with these exceptions: [ObjectDB 2.2.5_04] javax.persistence.RollbackException Failed to commit transaction: Optimistic lock failed for object   ... a second attempt after an optimistic exception (to improve performance). The behavior has nothing to do with client-server vs. ...

 
forum_thread

GWT RPC is throwing serialization exception when I have object db date value

Caused by: com.google.gwt.user.client.rpc.SerializationException: Type 'objectdb.java.util.Date' was not included in the set of types which can be serialized by this SerializationPolicy or its Class object could not be loaded. For security purposes, this type will not be serialized.: instance = Sat Jan 29 00:00:00 PST 2011    at com.google.gwt.user.server.rpc.impl.ServerSerializationStreamWriter.serialize(ServerSerializationStreamWriter.java:614)   #1 2011-02-07 15:14 Caused by: com.google.gwt.user.client.rpc.SerializationException: Type 'objectdb.java.util.Date' was not included i ...

 
tutorial

Step 4: Add a Servlet Class

Explains how to add a servlet that manages persistence using JPA and ObjectDB to an Eclipse Web Application. In this step we will add a servlet to manage guestbook web requests: Open the [Create Servlet] dialog box by right clicking the guest package node (in the [Package Explorer] window), selecting  New > Other... > Web > ...

 
tutorial

Step 4: Add a Servlet Class

Explains how to add a servlet that manages persistence using JPA and ObjectDB to a NetBeans Web Application. In this step we will add a servlet to manage guestbook web requests: Open the [New Servlet] dialog box by right clicking the guest package node (in the [Projects] window) and selecting New > Servlet ... Enter ...

 
forum_thread

Problem persisting a TreeSet field

Hello, I am getting a "java.lang.IllegalArgumentException: Can not set java.util.TreeSet field Message.children to java.util.HashSet" when persisting a Message object with a parent/children relationship: @ManyToOne private Message parent; @OneToMany(mappedBy = "parent") private TreeSet<Message> children; Seems that objectdb is converting TreeSet into HashSet? Why? http://www.objectdb.com/java/jpa/entity/types says TreeSet is supported... ... store collections, and actually avoiding them may improve performance as explained in the manual . ObjectDB ...