db4o Developer Community

I wondered if I should worry about this message that appeared during defragmentation (after closing and re-opening a database file with a db4o server application):14-Nov-2008 16:31:02 database.Db4oServer$DefragErrorListener notifyDefragmentInfoWARNING: Db4o Defragmentation Incident: No mapping found for ID 6523914-Nov-2008 16:31:02 ...

Hi, I had some time this week to look into the problem again, and I have managed to find what has caused the problem, or at least found a way to fix it for me... When I create the configuration, I call cfg.freespace().useRamSystem(); (just because I read that it would improve commit performance, and I expect my software to have many commits). ...

Hi Graham and Carl, Thanks for your help so far. I now removed all the code that used the ObjectContainer and its Configuration object. I also rewrote my stored objects so that they now store time in a java.util.Date instead of Calendar. Still, I get an error, immediately after the defrag method is called:SEVERE: Failed to defragment db4o file: ...

 Hi, I tried using the db4o defrag functionality on my database file, but sadly it failed. I can't make any sense from the exception. My log file looks like this: 06-Oct-2008 18:07:18 tvadb.database.Db4oFileDefrag openDatabaseINFO: Getting default db4o Configuration...06-Oct-2008 18:07:18 tvadb.database.Db4oFileDefrag openDatabaseINFO: ...

A common issue... http://developer.db4o.com/resources/api/db4o-java/ Goran

Using Java db4o 6.1.102 to build a database which is now around 330 MB.  Defrag is a recommended operation to keep the database lean and mean, but i'm having a problem. After using the ObjectManager ''Defrag'' option under the ''Manage'' menu (tried both 6.1 build 239, and 6.2 build 245), my database is reduced in size to ~ 230MB and i am no ...

Have you tried to defragment the database? http://developer.db4o.com/Resources/view.aspx/Reference/Tuning/Performance_Hints/Defragment Best regards,

hi All, We are using DB4o as our cache layer in our web-app - we get all the benefits of the B-Tree based system for free :). It works great. However there are couple of problems that keep surfacing intermittently all the time 1. S.O.D.A query doesnt fetch an object present in the db. We opened the file in ObjectManager and tried the same query, ...

Is there any specific configuration you've been using when creating the database? If so, please try whether it helps to pass an equivalent configuration via DefragmentConfig#db4oConfig(). Best regards,Patrick 

firepoet78:    Db4o.configure().objectClass(Identified.class).objectField(''id'').indexed(true);    Db4o.configure().objectClass(User.class).objectField(''username'').indexed(true); Here's how I run Defragment:           DefragmentConfig config = new ...