subgraph "logical_grouping" {
	style = rounded;
	bgcolor = gray95;
	color = gray;
	
	subgraph cluster_meta {
		label = <<b>meta</b>>;
		dbversion;
	}

	subgraph cluster_content {
		label = <<b>content</b>>;
		content;
	}

	subgraph cluster_directory {
		label = <<b>directories</b>>;
		directory;
		directory_entry_dir;
		directory_entry_file;
		directory_entry_rev;
		directory_list_dir;
		directory_list_file;
		directory_list_rev;
	}

	subgraph cluster_revision {
		label = <<b>revisions</b>>;
		revision;
		revision_history;
		person;
	}

	subgraph cluster_release {
		label = <<b>releases</b>>;
		release;
	}

	subgraph cluster_occurrences {
		label = <<b>occurrences</b>>;
		occurrence;
		occurrence_history;
	}

	subgraph cluster_origins {
		label = <<b>origins</b>>;
		origin;
		fetch_history;
	}

	subgraph cluster_projects {
		label = <<b>projects</b>>;
		project;
		project_history;
	}

	subgraph cluster_organization {
		label = <<b>organizations</b>>;
		organization;
		list_history;
	}

	{
		edge [style = dashed];

		directory_entry_file -> content;
		directory_entry_rev -> revision;
		revision -> directory;
	}

}