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/**
 *    Copyright (C) 2014 MongoDB Inc.
 *
 *    This program is free software: you can redistribute it and/or  modify
 *    it under the terms of the GNU Affero General Public License, version 3,
 *    as published by the Free Software Foundation.
 *
 *    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 Affero General Public License for more details.
 *
 *    You should have received a copy of the GNU Affero General Public License
 *    along with this program.  If not, see <http://www.gnu.org/licenses/>.
 *
 *    As a special exception, the copyright holders give permission to link the
 *    code of portions of this program with the OpenSSL library under certain
 *    conditions as described in each individual source file and distribute
 *    linked combinations including the program with the OpenSSL library. You
 *    must comply with the GNU Affero General Public License in all respects for
 *    all of the code used other than as permitted herein. If you modify file(s)
 *    with this exception, you may extend this exception to your version of the
 *    file(s), but you are not obligated to do so. If you do not wish to do so,
 *    delete this exception statement from your version. If you delete this
 *    exception statement from all source files in the program, then also delete
 *    it in the license file.
 */

#pragma once

namespace mongo {

//
// multi-plan ranking
//

// Max number of times we call work() on plans before comparing them,
// for small collections.
extern int internalQueryPlanEvaluationWorks;

// For large collections, the number times we work() candidate plans is
// taken as this fraction of the collection size.
extern double internalQueryPlanEvaluationCollFraction;

// Stop working plans once a plan returns this many results.
extern int internalQueryPlanEvaluationMaxResults;

// Do we give a big ranking bonus to intersection plans?
extern bool internalQueryForceIntersectionPlans;

// Do we have ixisect on at all?
extern bool internalQueryPlannerEnableIndexIntersection;

// Do we use hash-based intersection for rooted $and queries?
extern bool internalQueryPlannerEnableHashIntersection;

//
// plan cache
//

// How many entries in the cache?
extern int internalQueryCacheSize;

// How many feedback entries do we collect before possibly evicting from the cache based on bad
// performance?
extern int internalQueryCacheFeedbacksStored;

// How many stddevs must a feedback be from the 'reference' performance for us to evict the
// entry from the cache?
extern double internalQueryCacheStdDeviations;

// How many write ops should we allow in a collection before tossing all cache entries?
extern int internalQueryCacheWriteOpsBetweenFlush;

// Whether or not CachedPlanStage replanning is enabled.
extern bool internalQueryCacheReplanningEnabled;

// How many times more works must we perform in order to justify plan cache eviction and
// replanning?
extern double internalQueryCacheEvictionRatio;

//
// Planning and enumeration.
//

// How many indexed solutions will QueryPlanner::plan output?
extern int internalQueryPlannerMaxIndexedSolutions;

// How many solutions will the enumerator consider at each OR?
extern int internalQueryEnumerationMaxOrSolutions;

// How many intersections will the enumerator consider at each AND?
extern int internalQueryEnumerationMaxIntersectPerAnd;

// Do we want to plan each child of the OR independently?
extern bool internalQueryPlanOrChildrenIndependently;

// How many index scans are we willing to produce in order to obtain a sort order
// during explodeForSort?
extern int internalQueryMaxScansToExplode;

//
// Query execution.
//

extern int internalQueryExecMaxBlockingSortBytes;

// Yield after this many "should yield?" checks.
extern int internalQueryExecYieldIterations;

// Yield if it's been at least this many milliseconds since we last yielded.
extern int internalQueryExecYieldPeriodMS;

}  // namespace mongo