db4o Developer Community

Hello. I have some problem with db file.I'm using db4o in my application written in Java.User which uses it broke db file. I know that he updated application (replaced .jar file).New version of app has the same version db4o and the same settings.What was the immediate cause of this problem I don't know. But I have assumption, that he replaced .jar ...

Hello. I'm using a database with 1500 complex objects. When I make a query with a ''where'' clause the time it spends is around 0.7-1 second. The strange case happens if I remove the ''where'' clause, I supposed it should be faster than with it but the time increase to 20 seconds. Could you explain this to me, please?   Thanks! 

Hello! I'm doing some web services that use an embedded form of BD in db4o. When I make the request to a service any of the place, I create a static object ObjectServer for all services can use to access it, that is, the object instance in the form of BD Singleton. All services are functioning correctly if I go either locally or ...

ObjectSet<Pilot> set = db.query(Pilot.class);It's wrong while buiding above, why?? In tutorial docs ,        For JDK 5  there also is a generics shortcut, using the query method:      List <Pilot> pilots = db.query(Pilot.class); List<Pilot>? why not ...

Hi there,   I am building an application running on db4o 6.4.38.10595 and Java 1.6.02 and I encounter problems regarding Native Query optimization. I added a DiagnosticToConsole-listener which gives me the following error message: :: db4o 6.4.38.10595 Diagnostics ::  Native query not present. :: Native Query Optimizer could not be ...

hi,   I want to take back up of my yap on every day basis without stopping my tomcat server.  I have seen the ext().backup(''''); method and when i run my sample program then a error comes as   [db4o 6.1.602   2008-05-19 13:23:05]  Backups can not be run from clients and memory files.     can any ...

Hi everyone, I am a newbie. I am trying to use db4o to replace Hsqldb which we are using. And my use case is very simple. The DB only needs to store one type of object -- Employee. class Employee {    // id     // name     // ... other fields } However, the query speed is very slow ...

Hi I am a contributor to the google-guice community and open source java in general. We maintain integration modules between guice and several ORM frameworks. It seemed logical to have a db4objects alternative, and one of our contributors was kind enough to provide one. db4o is one of my long-time favorites, and we've had good success combining ...

Hi, Is there any way to create a blob file containing data that I have in memory rather than from an external file? My application splits images up into (potentially) hundreds of items, which need to be stored. I would prefer the database to handle this, so I'd like to use blobs rather than image files directly. It would be a nuisance if this ...

Hi All, I am currently working on a new web application (Netbeans 6.0 - Visual Web Components) and considering the use of Db4O for object persistence. I do not expect the application to have Google-like traffic anytime soon but I would like to design enough robustness to accommodate about 1 M dynamically-generated page views/month. I have ...