/**
Copyright (C) SYSTAP, LLC DBA Blazegraph 2006-2016. All rights reserved.
Contact:
SYSTAP, LLC DBA Blazegraph
2501 Calvert ST NW #106
Washington, DC 20008
licenses@blazegraph.com
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; version 2 of the License.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
/*
* Created on Oct 1, 2010
*/
package com.bigdata.btree;
/**
* B+Tree utilization report.
* <p>
* Note: The utilization numbers reported by this interface are a bit
* misleading. They only consider the #of index positions in the node or leaf
* which is full, but do not take into account the manner in which the
* persistence store allocates space to the node or leaf. For example, for the
* WORM we do perfect allocations but retain many versions. For the RWStore, we
* do best-fit allocations but recycle old versions. The space efficiency of the
* persistence store is typically the main driver, not the utilization rate as
* reported here.
*
* @author <a href="mailto:thompsonbry@users.sourceforge.net">Bryan Thompson</a>
* @version $Id: IBTreeUtilizationReport.java 3713 2010-10-01 15:36:09Z
* thompsonbry $
*/
public interface IBTreeUtilizationReport {
/**
* The leaf utilization percentage [0:100]. The leaf utilization is computed
* as the #of values stored in the tree divided by the #of values that could
* be stored in the #of allocated leaves.
*/
int getLeafUtilization();
/**
* The node utilization percentage [0:100]. The node utilization is computed
* as the #of non-root nodes divided by the #of non-root nodes that could be
* addressed by the tree.
*/
int getNodeUtilization();
/**
* The total utilization percentage [0:100]. This is the average of the leaf
* utilization and the node utilization.
*/
int getTotalUtilization();
}