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POOutOfMemoryError caused when db4o databse has 15000+ objects
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  1. POOutOfMemoryError caused when db4o databse has 15000+ objects
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    copied!<p>I am using db4o 8.0. </p> <p>I have a class </p> <pre><code>PostedMessage{ @Indexed long receivedTime; @Indexed long sentTime; ... //getter methods and setter methods for all the fields. } </code></pre> <p>I persist the PostedMessage objects to db4o database. I have already saved 15000+ objects to db4o database. And now when I run following query, it results in OutOfMemoryError.</p> <pre><code> //Query to get PostedMessages between "start" and "end" dates. Query q = db.query(); q.constrain(PostedMessage.class); Constraint from = q.descend("receivedTime").constrain(new Long(start.getTimeInMillis())).greater().equal(); q.descend("receivedTime").constrain(new Long(end.getTimeInMillis())).smaller().equal().and(from); q.execute();//results in OutOfMemoryError </code></pre> <p>To avoid the OutOfMemoryError, I need to add indexes to the fields of PostedMessage class. <a href="http://community.versant.com/Forums/tabid/98/aft/5258/Default.aspx" rel="nofollow">Read This</a>. </p> <p>I have a server/client configuration. I don't have control over pre-configuring the ObjectContainer before opening it.</p> <p>I will have to apply/append the indexing CommonConfiguration after the ObjectContainer is just opened and provided to me.</p> <p>I know how to create the config. </p> <pre><code> EmbeddedConfiguration appendConfig = Db4oEmbedded.newConfiguration(); appendConfig.common().objectClass(EmailMessage.class).objectField("receivedTime").indexed(true); appendConfig.common().objectClass(EmailMessage.class).objectField("sentTime").indexed(true); </code></pre> <p>I am not able to figure out how to apply this config to already opened ObjectContainer. How can I add indexes to the just opened ObjectContainer?</p> <p>Is <strong>EmbeddedConfigurationItem's apply()</strong> method the answer? If it is, can I get a sample code that shows how to use it?</p> <p>Edited : Added @Indexed annotation later to the question.</p>
 

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