/**
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
*/
package com.bigdata.bop.joinGraph.rto;
/**
* Type safe enumeration describes the edge condition (if any) for a cardinality
* estimate.
*/
public enum EstimateEnum {
/**
* An estimate, but not any of the edge conditions.
*/
Normal(" "),
/**
* The cardinality estimate is exact.
*/
Exact("E"),
/**
* The cardinality estimation is a lower bound (the actual cardinality may
* be higher than the estimated value).
* <p>
* Note: The estimated cardinality reported for a {@link #LowerBound} is the
* sum of the fast range counts for the sampled access paths. See the logic
* which handles cutoff join sampling for details on this.
*/
LowerBound("L"),
/**
* Flag is set when the cardinality estimate underflowed (false zero (0)).
*/
Underflow("U"),
;
private EstimateEnum(final String code) {
this.code = code;
}
private final String code;
public String getCode() {
return code;
}
}