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    <p>The short answer: Java garbage collection is a very finely tuned tool. System.gc() is a sledge-hammer.</p> <p>Java's heap is divided into different generations, each of which is collected using a different strategy. If you attach a profiler to a healthy app, you'll see that it very rarely has to run the most expensive kinds of collections because most objects are caught by the faster copying collector in the young generation.</p> <p>Calling System.gc() directly, while technically not guaranteed to do anything, in practice will trigger an expensive, stop-the-world full heap collection. This is <em>almost always the wrong thing to do</em>. You think you're saving resources, but you're actually wasting them for no good reason, forcing Java to recheck all your live objects “just in case”.</p> <p>If you are having problems with GC pauses during critical moments, you're better off configuring the JVM to use the concurrent mark/sweep collector, which was designed specifically to minimise time spent paused, than trying to take a sledgehammer to the problem and just breaking it further.</p> <p>The Sun document you were thinking of is here: <a href="http://java.sun.com/javase/technologies/hotspot/gc/gc_tuning_6.html" rel="noreferrer">Java SE 6 HotSpot&trade; Virtual Machine Garbage Collection Tuning</a></p> <p>(Another thing you might not know: implementing a finalize() method on your object makes garbage collection slower. Firstly, it will take <em>two</em> GC runs to collect the object: one to run finalize() and the next to ensure that the object wasn't resurrected during finalization. Secondly, objects with finalize() methods have to be treated as special cases by the GC because they have to be collected individually, they can't just be thrown away in bulk.)</p>
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Detail views are divided into sections. All the information in the data section comes from columns in the selected row. The other sections display data from other, related rows.

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