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/**
* Copyright (C) 2013 10gen 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
#include "mongo/base/status.h"
#include "mongo/db/exec/plan_stats.h"
#include "mongo/db/query/query_solution.h"
namespace mongo {
class TypeExplain;
struct PlanInfo;
/**
* Returns OK, allocating and filling in '*explainOut' describing the access paths used in
* the 'stats' tree of a given query solution. The caller has the ownership of
* '*explainOut', on success. Otherwise return an error status describing the problem.
*
* If 'fullDetails' was requested, the explain will return all available information about
* the plan, otherwise, just a summary. The fields in the summary are: 'cursor', 'n',
* 'nscannedObjects', 'nscanned', and 'indexBounds'. The remaining fields are: 'isMultKey',
* 'nscannedObjectsAllPlans', 'nscannedAllPlans', 'scanAndOrder', 'indexOnly', 'nYields',
* 'nChunkSkips', 'millis', 'allPlans', and 'oldPlan'.
*
* All these fields are documented in type_explain.h
*
* TODO: Currently, only working for single-leaf plans.
*/
Status explainPlan(const PlanStageStats& stats, TypeExplain** explainOut, bool fullDetails);
/**
* Returns OK, allocating and filling in '*explain' with details of
* the "winner" plan. Caller takes ownership of '*explain'. Otherwise,
* return a status describing the error.
*
* 'bestStats', 'candidateStats' and 'solution' are used to fill in '*explain'.
* Used by both MultiPlanRunner and CachedPlanRunner.
*/
Status explainMultiPlan(const PlanStageStats& stats,
const std::vector<PlanStageStats*>& candidateStats,
QuerySolution* solution,
TypeExplain** explain);
/**
* Returns a short plan summary std::string describing the leaves of the query solution.
*
* Used for logging.
*/
std::string getPlanSummary(const QuerySolution& soln);
/**
* If the out-parameter 'info' is non-null, fills in '*infoOut' with information
* from the query solution tree 'soln' that can be determined before the query is done
* running. Whereas 'explainPlan(...)' above is for collecting runtime debug information,
* this function is for collecting static debug information that is known prior
* to query runtime.
*
* The caller is responsible for deleting '*infoOut'.
*/
void getPlanInfo(const QuerySolution& soln, PlanInfo** infoOut);
void statsToBSON(const PlanStageStats& stats,
BSONObjBuilder* bob,
BSONObjBuilder* topLevelBob);
void statsToBSON(const PlanStageStats& stats, BSONObjBuilder* bob);
BSONObj statsToBSON(const PlanStageStats& stats);
} // namespace mongo
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