Bug 152919 [Import/Export] import existing project w/ copy is inefficient
I just tried to import some existing projects and selected "copy projects into workspace". After a long time (sorry, no measurements) I had to cancel the request, because I was running out of disk space. I had just succeeded in importing the first project (jdt core), which takes approx. 80MB disk space, but at that time the previously blank workspace consumed additional 300MB mainly in: .metadata/.plugins/org.eclipse.core.resources/.history/ Is this operation recording undo-information for each single file imported? Unless I made something really stupid, this operation seems not to be usable for large projects.
bundles/org.eclipse.ui.ide/src/org/eclipse/ui/internal/wizards/datatransfer/WizardProjectsImportPage.java
*            The monitor to report to
	 * @return boolean <code>true</code> if the operation was completed.
	 */
	private boolean collectProjectFilesFromProvider(Collection files,
			ILeveledImportStructureProvider provider, Object entry, int level,
			IProgressMonitor monitor) {
		if (monitor.isCanceled()) {
			return false;
		}
		monitor.subTask(NLS.bind(
				DataTransferMessages.WizardProjectsImportPage_CheckingMessage,
				provider.getLabel(entry)));
		List children = provider.getChildren(entry);
		if (children == null) {
			children = new ArrayList(1);
		}
		Iterator childrenEnum = children.iterator();
		while (childrenEnum.hasNext()) {
			Object child = childrenEnum.next();
			if (provider.isFolder(child)) {
				collectProjectFilesFromProvider(files, provider, child,
						level + 1, monitor);
			}
			String elementLabel = provider.getLabel(child);
			if (elementLabel.equals(IProjectDescription.DESCRIPTION_FILE_NAME)) {
				files.add(new ProjectRecord(child, entry, level, provider));
			}
		}
		return true;
	}