Status SubplanRunner::planSubqueries() {
MatchExpression* theOr = _query->root();
for (size_t i = 0; i < _plannerParams.indices.size(); ++i) {
const IndexEntry& ie = _plannerParams.indices[i];
_indexMap[ie.keyPattern] = i;
QLOG() << "Subplanner: index " << i << " is " << ie.toString() << endl;
}
const WhereCallbackReal whereCallback(_collection->ns().db());
for (size_t i = 0; i < theOr->numChildren(); ++i) {
// Turn the i-th child into its own query.
MatchExpression* orChild = theOr->getChild(i);
CanonicalQuery* orChildCQ;
Status childCQStatus = CanonicalQuery::canonicalize(*_query,
orChild,
&orChildCQ,
whereCallback);
if (!childCQStatus.isOK()) {
mongoutils::str::stream ss;
ss << "Subplanner: Can't canonicalize subchild " << orChild->toString()
<< " " << childCQStatus.reason();
return Status(ErrorCodes::BadValue, ss);
}
// Make sure it gets cleaned up.
auto_ptr<CanonicalQuery> safeOrChildCQ(orChildCQ);
// Plan the i-th child.
vector<QuerySolution*> solutions;
// We don't set NO_TABLE_SCAN because peeking at the cache data will keep us from
// considering any plan that's a collscan.
QLOG() << "Subplanner: planning child " << i << " of " << theOr->numChildren();
Status status = QueryPlanner::plan(*safeOrChildCQ, _plannerParams, &solutions);
if (!status.isOK()) {
mongoutils::str::stream ss;
ss << "Subplanner: Can't plan for subchild " << orChildCQ->toString()
<< " " << status.reason();
return Status(ErrorCodes::BadValue, ss);
}
QLOG() << "Subplanner: got " << solutions.size() << " solutions";
if (0 == solutions.size()) {
// If one child doesn't have an indexed solution, bail out.
mongoutils::str::stream ss;
ss << "Subplanner: No solutions for subchild " << orChildCQ->toString();
return Status(ErrorCodes::BadValue, ss);
}
// Hang onto the canonicalized subqueries and the corresponding query solutions
// so that they can be used in subplan running later on.
_cqs.push(safeOrChildCQ.release());
_solutions.push(solutions);
}
return Status::OK();
}
Status SubplanStage::choosePlanForSubqueries(PlanYieldPolicy* yieldPolicy) {
// This is what we annotate with the index selections and then turn into a solution.
auto_ptr<OrMatchExpression> orExpr(
static_cast<OrMatchExpression*>(_query->root()->shallowClone()));
// This is the skeleton of index selections that is inserted into the cache.
auto_ptr<PlanCacheIndexTree> cacheData(new PlanCacheIndexTree());
for (size_t i = 0; i < orExpr->numChildren(); ++i) {
MatchExpression* orChild = orExpr->getChild(i);
BranchPlanningResult* branchResult = _branchResults[i];
if (branchResult->cachedSolution.get()) {
// We can get the index tags we need out of the cache.
Status tagStatus = tagOrChildAccordingToCache(
cacheData.get(),
branchResult->cachedSolution->plannerData[0],
orChild,
_indexMap);
if (!tagStatus.isOK()) {
return tagStatus;
}
}
else if (1 == branchResult->solutions.size()) {
QuerySolution* soln = branchResult->solutions.front();
Status tagStatus = tagOrChildAccordingToCache(cacheData.get(),
soln->cacheData.get(),
orChild,
_indexMap);
if (!tagStatus.isOK()) {
return tagStatus;
}
}
else {
// N solutions, rank them.
// We already checked for zero solutions in planSubqueries(...).
invariant(!branchResult->solutions.empty());
_ws->clear();
_child.reset(new MultiPlanStage(_txn, _collection,
branchResult->canonicalQuery.get()));
MultiPlanStage* multiPlanStage = static_cast<MultiPlanStage*>(_child.get());
// Dump all the solutions into the MPS.
for (size_t ix = 0; ix < branchResult->solutions.size(); ++ix) {
PlanStage* nextPlanRoot;
invariant(StageBuilder::build(_txn,
_collection,
*branchResult->solutions[ix],
_ws,
&nextPlanRoot));
// Takes ownership of solution with index 'ix' and 'nextPlanRoot'.
multiPlanStage->addPlan(branchResult->solutions.releaseAt(ix),
nextPlanRoot,
_ws);
}
Status planSelectStat = multiPlanStage->pickBestPlan(yieldPolicy);
if (!planSelectStat.isOK()) {
return planSelectStat;
}
if (!multiPlanStage->bestPlanChosen()) {
mongoutils::str::stream ss;
ss << "Failed to pick best plan for subchild "
<< branchResult->canonicalQuery->toString();
return Status(ErrorCodes::BadValue, ss);
}
QuerySolution* bestSoln = multiPlanStage->bestSolution();
// Check that we have good cache data. For example, we don't cache things
// for 2d indices.
if (NULL == bestSoln->cacheData.get()) {
mongoutils::str::stream ss;
ss << "No cache data for subchild " << orChild->toString();
return Status(ErrorCodes::BadValue, ss);
}
if (SolutionCacheData::USE_INDEX_TAGS_SOLN != bestSoln->cacheData->solnType) {
mongoutils::str::stream ss;
ss << "No indexed cache data for subchild "
<< orChild->toString();
return Status(ErrorCodes::BadValue, ss);
}
// Add the index assignments to our original query.
Status tagStatus = QueryPlanner::tagAccordingToCache(
orChild, bestSoln->cacheData->tree.get(), _indexMap);
if (!tagStatus.isOK()) {
mongoutils::str::stream ss;
ss << "Failed to extract indices from subchild "
<< orChild->toString();
return Status(ErrorCodes::BadValue, ss);
}
cacheData->children.push_back(bestSoln->cacheData->tree->clone());
}
}
// Must do this before using the planner functionality.
sortUsingTags(orExpr.get());
// Use the cached index assignments to build solnRoot. Takes ownership of 'orExpr'.
QuerySolutionNode* solnRoot = QueryPlannerAccess::buildIndexedDataAccess(
*_query, orExpr.release(), false, _plannerParams.indices, _plannerParams);
if (NULL == solnRoot) {
mongoutils::str::stream ss;
ss << "Failed to build indexed data path for subplanned query\n";
return Status(ErrorCodes::BadValue, ss);
}
QLOG() << "Subplanner: fully tagged tree is " << solnRoot->toString();
// Takes ownership of 'solnRoot'
_compositeSolution.reset(QueryPlannerAnalysis::analyzeDataAccess(*_query,
_plannerParams,
solnRoot));
if (NULL == _compositeSolution.get()) {
mongoutils::str::stream ss;
ss << "Failed to analyze subplanned query";
return Status(ErrorCodes::BadValue, ss);
}
QLOG() << "Subplanner: Composite solution is " << _compositeSolution->toString() << endl;
// Use the index tags from planning each branch to construct the composite solution,
// and set that solution as our child stage.
_ws->clear();
PlanStage* root;
invariant(StageBuilder::build(_txn, _collection, *_compositeSolution.get(), _ws, &root));
_child.reset(root);
return Status::OK();
}
Status SubplanStage::planSubqueries() {
// Adds the amount of time taken by planSubqueries() to executionTimeMillis. There's lots of
// work that happens here, so this is needed for the time accounting to make sense.
ScopedTimer timer(&_commonStats.executionTimeMillis);
MatchExpression* orExpr = _query->root();
for (size_t i = 0; i < _plannerParams.indices.size(); ++i) {
const IndexEntry& ie = _plannerParams.indices[i];
_indexMap[ie.keyPattern] = i;
QLOG() << "Subplanner: index " << i << " is " << ie.toString() << endl;
}
const WhereCallbackReal whereCallback(_txn, _collection->ns().db());
for (size_t i = 0; i < orExpr->numChildren(); ++i) {
// We need a place to shove the results from planning this branch.
_branchResults.push_back(new BranchPlanningResult());
BranchPlanningResult* branchResult = _branchResults.back();
MatchExpression* orChild = orExpr->getChild(i);
// Turn the i-th child into its own query.
{
CanonicalQuery* orChildCQ;
Status childCQStatus = CanonicalQuery::canonicalize(*_query,
orChild,
&orChildCQ,
whereCallback);
if (!childCQStatus.isOK()) {
mongoutils::str::stream ss;
ss << "Can't canonicalize subchild " << orChild->toString()
<< " " << childCQStatus.reason();
return Status(ErrorCodes::BadValue, ss);
}
branchResult->canonicalQuery.reset(orChildCQ);
}
// Plan the i-th child. We might be able to find a plan for the i-th child in the plan
// cache. If there's no cached plan, then we generate and rank plans using the MPS.
CachedSolution* rawCS;
if (PlanCache::shouldCacheQuery(*branchResult->canonicalQuery.get()) &&
_collection->infoCache()->getPlanCache()->get(*branchResult->canonicalQuery.get(),
&rawCS).isOK()) {
// We have a CachedSolution. Store it for later.
QLOG() << "Subplanner: cached plan found for child " << i << " of "
<< orExpr->numChildren();
branchResult->cachedSolution.reset(rawCS);
}
else {
// No CachedSolution found. We'll have to plan from scratch.
QLOG() << "Subplanner: planning child " << i << " of " << orExpr->numChildren();
// We don't set NO_TABLE_SCAN because peeking at the cache data will keep us from
// considering any plan that's a collscan.
Status status = QueryPlanner::plan(*branchResult->canonicalQuery.get(),
_plannerParams,
&branchResult->solutions.mutableVector());
if (!status.isOK()) {
mongoutils::str::stream ss;
ss << "Can't plan for subchild "
<< branchResult->canonicalQuery->toString()
<< " " << status.reason();
return Status(ErrorCodes::BadValue, ss);
}
QLOG() << "Subplanner: got " << branchResult->solutions.size() << " solutions";
if (0 == branchResult->solutions.size()) {
// If one child doesn't have an indexed solution, bail out.
mongoutils::str::stream ss;
ss << "No solutions for subchild " << branchResult->canonicalQuery->toString();
return Status(ErrorCodes::BadValue, ss);
}
}
}
return Status::OK();
}
Status SubplanStage::choosePlanForSubqueries(PlanYieldPolicy* yieldPolicy) {
// This is the skeleton of index selections that is inserted into the cache.
std::unique_ptr<PlanCacheIndexTree> cacheData(new PlanCacheIndexTree());
for (size_t i = 0; i < _orExpression->numChildren(); ++i) {
MatchExpression* orChild = _orExpression->getChild(i);
BranchPlanningResult* branchResult = _branchResults[i].get();
if (branchResult->cachedSolution.get()) {
// We can get the index tags we need out of the cache.
Status tagStatus = tagOrChildAccordingToCache(
cacheData.get(), branchResult->cachedSolution->plannerData[0], orChild, _indexMap);
if (!tagStatus.isOK()) {
return tagStatus;
}
} else if (1 == branchResult->solutions.size()) {
QuerySolution* soln = branchResult->solutions.front().get();
Status tagStatus = tagOrChildAccordingToCache(
cacheData.get(), soln->cacheData.get(), orChild, _indexMap);
if (!tagStatus.isOK()) {
return tagStatus;
}
} else {
// N solutions, rank them.
// We already checked for zero solutions in planSubqueries(...).
invariant(!branchResult->solutions.empty());
_ws->clear();
// We pass the SometimesCache option to the MPS because the SubplanStage currently does
// not use the CachedPlanStage's eviction mechanism. We therefore are more conservative
// about putting a potentially bad plan into the cache in the subplan path.
// We temporarily add the MPS to _children to ensure that we pass down all
// save/restore/invalidate messages that can be generated if pickBestPlan yields.
invariant(_children.empty());
_children.emplace_back(
stdx::make_unique<MultiPlanStage>(getOpCtx(),
_collection,
branchResult->canonicalQuery.get(),
MultiPlanStage::CachingMode::SometimesCache));
ON_BLOCK_EXIT([&] {
invariant(_children.size() == 1); // Make sure nothing else was added to _children.
_children.pop_back();
});
MultiPlanStage* multiPlanStage = static_cast<MultiPlanStage*>(child().get());
// Dump all the solutions into the MPS.
for (size_t ix = 0; ix < branchResult->solutions.size(); ++ix) {
PlanStage* nextPlanRoot;
invariant(StageBuilder::build(getOpCtx(),
_collection,
*branchResult->canonicalQuery,
*branchResult->solutions[ix],
_ws,
&nextPlanRoot));
// Takes ownership of 'nextPlanRoot'.
multiPlanStage->addPlan(std::move(branchResult->solutions[ix]), nextPlanRoot, _ws);
}
Status planSelectStat = multiPlanStage->pickBestPlan(yieldPolicy);
if (!planSelectStat.isOK()) {
return planSelectStat;
}
if (!multiPlanStage->bestPlanChosen()) {
mongoutils::str::stream ss;
ss << "Failed to pick best plan for subchild "
<< branchResult->canonicalQuery->toString();
return Status(ErrorCodes::BadValue, ss);
}
QuerySolution* bestSoln = multiPlanStage->bestSolution();
// Check that we have good cache data. For example, we don't cache things
// for 2d indices.
if (NULL == bestSoln->cacheData.get()) {
mongoutils::str::stream ss;
ss << "No cache data for subchild " << orChild->toString();
return Status(ErrorCodes::BadValue, ss);
}
if (SolutionCacheData::USE_INDEX_TAGS_SOLN != bestSoln->cacheData->solnType) {
mongoutils::str::stream ss;
ss << "No indexed cache data for subchild " << orChild->toString();
return Status(ErrorCodes::BadValue, ss);
}
// Add the index assignments to our original query.
Status tagStatus = QueryPlanner::tagAccordingToCache(
orChild, bestSoln->cacheData->tree.get(), _indexMap);
if (!tagStatus.isOK()) {
mongoutils::str::stream ss;
ss << "Failed to extract indices from subchild " << orChild->toString();
return Status(ErrorCodes::BadValue, ss);
}
cacheData->children.push_back(bestSoln->cacheData->tree->clone());
}
}
// Must do this before using the planner functionality.
prepareForAccessPlanning(_orExpression.get());
// Use the cached index assignments to build solnRoot. Takes ownership of '_orExpression'.
std::unique_ptr<QuerySolutionNode> solnRoot(QueryPlannerAccess::buildIndexedDataAccess(
*_query, std::move(_orExpression), _plannerParams.indices, _plannerParams));
if (!solnRoot) {
mongoutils::str::stream ss;
ss << "Failed to build indexed data path for subplanned query\n";
return Status(ErrorCodes::BadValue, ss);
}
LOG(5) << "Subplanner: fully tagged tree is " << redact(solnRoot->toString());
// Takes ownership of 'solnRoot'
_compositeSolution =
QueryPlannerAnalysis::analyzeDataAccess(*_query, _plannerParams, std::move(solnRoot));
if (NULL == _compositeSolution.get()) {
mongoutils::str::stream ss;
ss << "Failed to analyze subplanned query";
return Status(ErrorCodes::BadValue, ss);
}
LOG(5) << "Subplanner: Composite solution is " << redact(_compositeSolution->toString());
// Use the index tags from planning each branch to construct the composite solution,
// and set that solution as our child stage.
_ws->clear();
PlanStage* root;
invariant(StageBuilder::build(
getOpCtx(), _collection, *_query, *_compositeSolution.get(), _ws, &root));
invariant(_children.empty());
_children.emplace_back(root);
return Status::OK();
}
Status SubplanStage::planSubqueries() {
_orExpression = _query->root()->shallowClone();
for (size_t i = 0; i < _plannerParams.indices.size(); ++i) {
const IndexEntry& ie = _plannerParams.indices[i];
_indexMap[ie.name] = i;
LOG(5) << "Subplanner: index " << i << " is " << ie;
}
for (size_t i = 0; i < _orExpression->numChildren(); ++i) {
// We need a place to shove the results from planning this branch.
_branchResults.push_back(stdx::make_unique<BranchPlanningResult>());
BranchPlanningResult* branchResult = _branchResults.back().get();
MatchExpression* orChild = _orExpression->getChild(i);
// Turn the i-th child into its own query.
auto statusWithCQ = CanonicalQuery::canonicalize(getOpCtx(), *_query, orChild);
if (!statusWithCQ.isOK()) {
mongoutils::str::stream ss;
ss << "Can't canonicalize subchild " << orChild->toString() << " "
<< statusWithCQ.getStatus().reason();
return Status(ErrorCodes::BadValue, ss);
}
branchResult->canonicalQuery = std::move(statusWithCQ.getValue());
// Plan the i-th child. We might be able to find a plan for the i-th child in the plan
// cache. If there's no cached plan, then we generate and rank plans using the MPS.
const auto* planCache = _collection->infoCache()->getPlanCache();
if (auto cachedSol = planCache->getCacheEntryIfCacheable(*branchResult->canonicalQuery)) {
// We have a CachedSolution. Store it for later.
LOG(5) << "Subplanner: cached plan found for child " << i << " of "
<< _orExpression->numChildren();
branchResult->cachedSolution = std::move(cachedSol);
} else {
// No CachedSolution found. We'll have to plan from scratch.
LOG(5) << "Subplanner: planning child " << i << " of " << _orExpression->numChildren();
// We don't set NO_TABLE_SCAN because peeking at the cache data will keep us from
// considering any plan that's a collscan.
invariant(branchResult->solutions.empty());
auto solutions = QueryPlanner::plan(*branchResult->canonicalQuery, _plannerParams);
if (!solutions.isOK()) {
mongoutils::str::stream ss;
ss << "Can't plan for subchild " << branchResult->canonicalQuery->toString() << " "
<< solutions.getStatus().reason();
return Status(ErrorCodes::BadValue, ss);
}
branchResult->solutions = std::move(solutions.getValue());
LOG(5) << "Subplanner: got " << branchResult->solutions.size() << " solutions";
if (0 == branchResult->solutions.size()) {
// If one child doesn't have an indexed solution, bail out.
mongoutils::str::stream ss;
ss << "No solutions for subchild " << branchResult->canonicalQuery->toString();
return Status(ErrorCodes::BadValue, ss);
}
}
}
return Status::OK();
}
// static
Status QueryPlanner::plan(const CanonicalQuery& query,
const QueryPlannerParams& params,
std::vector<QuerySolution*>* out) {
LOG(5) << "Beginning planning..." << endl
<< "=============================" << endl
<< "Options = " << optionString(params.options) << endl
<< "Canonical query:" << endl
<< query.toString() << "=============================" << endl;
for (size_t i = 0; i < params.indices.size(); ++i) {
LOG(5) << "Index " << i << " is " << params.indices[i].toString() << endl;
}
bool canTableScan = !(params.options & QueryPlannerParams::NO_TABLE_SCAN);
// If the query requests a tailable cursor, the only solution is a collscan + filter with
// tailable set on the collscan. TODO: This is a policy departure. Previously I think you
// could ask for a tailable cursor and it just tried to give you one. Now, we fail if we
// can't provide one. Is this what we want?
if (query.getParsed().isTailable()) {
if (!QueryPlannerCommon::hasNode(query.root(), MatchExpression::GEO_NEAR) && canTableScan) {
QuerySolution* soln = buildCollscanSoln(query, true, params);
if (NULL != soln) {
out->push_back(soln);
}
}
return Status::OK();
}
// The hint or sort can be $natural: 1. If this happens, output a collscan. If both
// a $natural hint and a $natural sort are specified, then the direction of the collscan
// is determined by the sign of the sort (not the sign of the hint).
if (!query.getParsed().getHint().isEmpty() || !query.getParsed().getSort().isEmpty()) {
BSONObj hintObj = query.getParsed().getHint();
BSONObj sortObj = query.getParsed().getSort();
BSONElement naturalHint = hintObj.getFieldDotted("$natural");
BSONElement naturalSort = sortObj.getFieldDotted("$natural");
// A hint overrides a $natural sort. This means that we don't force a table
// scan if there is a $natural sort with a non-$natural hint.
if (!naturalHint.eoo() || (!naturalSort.eoo() && hintObj.isEmpty())) {
LOG(5) << "Forcing a table scan due to hinted $natural\n";
// min/max are incompatible with $natural.
if (canTableScan && query.getParsed().getMin().isEmpty() &&
query.getParsed().getMax().isEmpty()) {
QuerySolution* soln = buildCollscanSoln(query, false, params);
if (NULL != soln) {
out->push_back(soln);
}
}
return Status::OK();
}
}
// Figure out what fields we care about.
unordered_set<string> fields;
QueryPlannerIXSelect::getFields(query.root(), "", &fields);
for (unordered_set<string>::const_iterator it = fields.begin(); it != fields.end(); ++it) {
LOG(5) << "Predicate over field '" << *it << "'" << endl;
}
// Filter our indices so we only look at indices that are over our predicates.
vector<IndexEntry> relevantIndices;
// Hints require us to only consider the hinted index.
// If index filters in the query settings were used to override
// the allowed indices for planning, we should not use the hinted index
// requested in the query.
BSONObj hintIndex;
if (!params.indexFiltersApplied) {
hintIndex = query.getParsed().getHint();
}
// Snapshot is a form of a hint. If snapshot is set, try to use _id index to make a real
// plan. If that fails, just scan the _id index.
if (query.getParsed().isSnapshot()) {
// Find the ID index in indexKeyPatterns. It's our hint.
for (size_t i = 0; i < params.indices.size(); ++i) {
if (isIdIndex(params.indices[i].keyPattern)) {
hintIndex = params.indices[i].keyPattern;
break;
}
}
}
size_t hintIndexNumber = numeric_limits<size_t>::max();
if (hintIndex.isEmpty()) {
QueryPlannerIXSelect::findRelevantIndices(fields, params.indices, &relevantIndices);
} else {
// Sigh. If the hint is specified it might be using the index name.
BSONElement firstHintElt = hintIndex.firstElement();
if (str::equals("$hint", firstHintElt.fieldName()) && String == firstHintElt.type()) {
string hintName = firstHintElt.String();
for (size_t i = 0; i < params.indices.size(); ++i) {
if (params.indices[i].name == hintName) {
LOG(5) << "Hint by name specified, restricting indices to "
<< params.indices[i].keyPattern.toString() << endl;
relevantIndices.clear();
relevantIndices.push_back(params.indices[i]);
hintIndexNumber = i;
hintIndex = params.indices[i].keyPattern;
break;
}
}
} else {
for (size_t i = 0; i < params.indices.size(); ++i) {
if (0 == params.indices[i].keyPattern.woCompare(hintIndex)) {
relevantIndices.clear();
relevantIndices.push_back(params.indices[i]);
LOG(5) << "Hint specified, restricting indices to " << hintIndex.toString()
<< endl;
hintIndexNumber = i;
break;
}
}
}
if (hintIndexNumber == numeric_limits<size_t>::max()) {
return Status(ErrorCodes::BadValue, "bad hint");
}
}
// Deal with the .min() and .max() query options. If either exist we can only use an index
// that matches the object inside.
if (!query.getParsed().getMin().isEmpty() || !query.getParsed().getMax().isEmpty()) {
BSONObj minObj = query.getParsed().getMin();
BSONObj maxObj = query.getParsed().getMax();
// The unfinished siblings of these objects may not be proper index keys because they
// may be empty objects or have field names. When an index is picked to use for the
// min/max query, these "finished" objects will always be valid index keys for the
// index's key pattern.
BSONObj finishedMinObj;
BSONObj finishedMaxObj;
// This is the index into params.indices[...] that we use.
size_t idxNo = numeric_limits<size_t>::max();
// If there's an index hinted we need to be able to use it.
if (!hintIndex.isEmpty()) {
if (!minObj.isEmpty() && !indexCompatibleMaxMin(minObj, hintIndex)) {
LOG(5) << "Minobj doesn't work with hint";
return Status(ErrorCodes::BadValue, "hint provided does not work with min query");
}
if (!maxObj.isEmpty() && !indexCompatibleMaxMin(maxObj, hintIndex)) {
LOG(5) << "Maxobj doesn't work with hint";
return Status(ErrorCodes::BadValue, "hint provided does not work with max query");
}
const BSONObj& kp = params.indices[hintIndexNumber].keyPattern;
finishedMinObj = finishMinObj(kp, minObj, maxObj);
finishedMaxObj = finishMaxObj(kp, minObj, maxObj);
// The min must be less than the max for the hinted index ordering.
if (0 <= finishedMinObj.woCompare(finishedMaxObj, kp, false)) {
LOG(5) << "Minobj/Maxobj don't work with hint";
return Status(ErrorCodes::BadValue,
"hint provided does not work with min/max query");
}
idxNo = hintIndexNumber;
} else {
// No hinted index, look for one that is compatible (has same field names and
// ordering thereof).
for (size_t i = 0; i < params.indices.size(); ++i) {
const BSONObj& kp = params.indices[i].keyPattern;
BSONObj toUse = minObj.isEmpty() ? maxObj : minObj;
if (indexCompatibleMaxMin(toUse, kp)) {
// In order to be fully compatible, the min has to be less than the max
// according to the index key pattern ordering. The first step in verifying
// this is "finish" the min and max by replacing empty objects and stripping
// field names.
finishedMinObj = finishMinObj(kp, minObj, maxObj);
finishedMaxObj = finishMaxObj(kp, minObj, maxObj);
// Now we have the final min and max. This index is only relevant for
// the min/max query if min < max.
if (0 >= finishedMinObj.woCompare(finishedMaxObj, kp, false)) {
// Found a relevant index.
idxNo = i;
break;
}
// This index is not relevant; move on to the next.
}
}
}
if (idxNo == numeric_limits<size_t>::max()) {
LOG(5) << "Can't find relevant index to use for max/min query";
// Can't find an index to use, bail out.
return Status(ErrorCodes::BadValue, "unable to find relevant index for max/min query");
}
LOG(5) << "Max/min query using index " << params.indices[idxNo].toString() << endl;
// Make our scan and output.
QuerySolutionNode* solnRoot = QueryPlannerAccess::makeIndexScan(
params.indices[idxNo], query, params, finishedMinObj, finishedMaxObj);
QuerySolution* soln = QueryPlannerAnalysis::analyzeDataAccess(query, params, solnRoot);
if (NULL != soln) {
out->push_back(soln);
}
return Status::OK();
}
for (size_t i = 0; i < relevantIndices.size(); ++i) {
LOG(2) << "Relevant index " << i << " is " << relevantIndices[i].toString() << endl;
}
// Figure out how useful each index is to each predicate.
QueryPlannerIXSelect::rateIndices(query.root(), "", relevantIndices);
QueryPlannerIXSelect::stripInvalidAssignments(query.root(), relevantIndices);
// Unless we have GEO_NEAR, TEXT, or a projection, we may be able to apply an optimization
// in which we strip unnecessary index assignments.
//
// Disallowed with projection because assignment to a non-unique index can allow the plan
// to be covered.
//
// TEXT and GEO_NEAR are special because they require the use of a text/geo index in order
// to be evaluated correctly. Stripping these "mandatory assignments" is therefore invalid.
if (query.getParsed().getProj().isEmpty() &&
!QueryPlannerCommon::hasNode(query.root(), MatchExpression::GEO_NEAR) &&
!QueryPlannerCommon::hasNode(query.root(), MatchExpression::TEXT)) {
QueryPlannerIXSelect::stripUnneededAssignments(query.root(), relevantIndices);
}
// query.root() is now annotated with RelevantTag(s).
LOG(5) << "Rated tree:" << endl
<< query.root()->toString();
// If there is a GEO_NEAR it must have an index it can use directly.
MatchExpression* gnNode = NULL;
if (QueryPlannerCommon::hasNode(query.root(), MatchExpression::GEO_NEAR, &gnNode)) {
// No index for GEO_NEAR? No query.
RelevantTag* tag = static_cast<RelevantTag*>(gnNode->getTag());
if (0 == tag->first.size() && 0 == tag->notFirst.size()) {
LOG(5) << "Unable to find index for $geoNear query." << endl;
// Don't leave tags on query tree.
query.root()->resetTag();
return Status(ErrorCodes::BadValue, "unable to find index for $geoNear query");
}
LOG(5) << "Rated tree after geonear processing:" << query.root()->toString();
}
// Likewise, if there is a TEXT it must have an index it can use directly.
MatchExpression* textNode = NULL;
if (QueryPlannerCommon::hasNode(query.root(), MatchExpression::TEXT, &textNode)) {
RelevantTag* tag = static_cast<RelevantTag*>(textNode->getTag());
// Exactly one text index required for TEXT. We need to check this explicitly because
// the text stage can't be built if no text index exists or there is an ambiguity as to
// which one to use.
size_t textIndexCount = 0;
for (size_t i = 0; i < params.indices.size(); i++) {
if (INDEX_TEXT == params.indices[i].type) {
textIndexCount++;
}
}
if (textIndexCount != 1) {
// Don't leave tags on query tree.
query.root()->resetTag();
return Status(ErrorCodes::BadValue, "need exactly one text index for $text query");
}
// Error if the text node is tagged with zero indices.
if (0 == tag->first.size() && 0 == tag->notFirst.size()) {
// Don't leave tags on query tree.
query.root()->resetTag();
return Status(ErrorCodes::BadValue,
"failed to use text index to satisfy $text query (if text index is "
"compound, are equality predicates given for all prefix fields?)");
}
// At this point, we know that there is only one text index and that the TEXT node is
// assigned to it.
invariant(1 == tag->first.size() + tag->notFirst.size());
LOG(5) << "Rated tree after text processing:" << query.root()->toString();
}
// If we have any relevant indices, we try to create indexed plans.
if (0 < relevantIndices.size()) {
// The enumerator spits out trees tagged with IndexTag(s).
PlanEnumeratorParams enumParams;
enumParams.intersect = params.options & QueryPlannerParams::INDEX_INTERSECTION;
enumParams.root = query.root();
enumParams.indices = &relevantIndices;
PlanEnumerator isp(enumParams);
isp.init();
MatchExpression* rawTree;
while (isp.getNext(&rawTree) && (out->size() < params.maxIndexedSolutions)) {
LOG(5) << "About to build solntree from tagged tree:" << endl
<< rawTree->toString();
// The tagged tree produced by the plan enumerator is not guaranteed
// to be canonically sorted. In order to be compatible with the cached
// data, sort the tagged tree according to CanonicalQuery ordering.
std::unique_ptr<MatchExpression> clone(rawTree->shallowClone());
CanonicalQuery::sortTree(clone.get());
PlanCacheIndexTree* cacheData;
Status indexTreeStatus =
cacheDataFromTaggedTree(clone.get(), relevantIndices, &cacheData);
if (!indexTreeStatus.isOK()) {
LOG(5) << "Query is not cachable: " << indexTreeStatus.reason() << endl;
}
unique_ptr<PlanCacheIndexTree> autoData(cacheData);
// This can fail if enumeration makes a mistake.
QuerySolutionNode* solnRoot = QueryPlannerAccess::buildIndexedDataAccess(
query, rawTree, false, relevantIndices, params);
if (NULL == solnRoot) {
continue;
}
QuerySolution* soln = QueryPlannerAnalysis::analyzeDataAccess(query, params, solnRoot);
if (NULL != soln) {
LOG(5) << "Planner: adding solution:" << endl
<< soln->toString();
if (indexTreeStatus.isOK()) {
SolutionCacheData* scd = new SolutionCacheData();
scd->tree.reset(autoData.release());
soln->cacheData.reset(scd);
}
out->push_back(soln);
}
}
}
// Don't leave tags on query tree.
query.root()->resetTag();
LOG(5) << "Planner: outputted " << out->size() << " indexed solutions.\n";
// Produce legible error message for failed OR planning with a TEXT child.
// TODO: support collection scan for non-TEXT children of OR.
if (out->size() == 0 && textNode != NULL && MatchExpression::OR == query.root()->matchType()) {
MatchExpression* root = query.root();
for (size_t i = 0; i < root->numChildren(); ++i) {
if (textNode == root->getChild(i)) {
return Status(ErrorCodes::BadValue,
"Failed to produce a solution for TEXT under OR - "
"other non-TEXT clauses under OR have to be indexed as well.");
}
}
}
// An index was hinted. If there are any solutions, they use the hinted index. If not, we
// scan the entire index to provide results and output that as our plan. This is the
// desired behavior when an index is hinted that is not relevant to the query.
if (!hintIndex.isEmpty()) {
if (0 == out->size()) {
QuerySolution* soln = buildWholeIXSoln(params.indices[hintIndexNumber], query, params);
verify(NULL != soln);
LOG(5) << "Planner: outputting soln that uses hinted index as scan." << endl;
out->push_back(soln);
}
return Status::OK();
}
// If a sort order is requested, there may be an index that provides it, even if that
// index is not over any predicates in the query.
//
if (!query.getParsed().getSort().isEmpty() &&
!QueryPlannerCommon::hasNode(query.root(), MatchExpression::GEO_NEAR) &&
!QueryPlannerCommon::hasNode(query.root(), MatchExpression::TEXT)) {
// See if we have a sort provided from an index already.
// This is implied by the presence of a non-blocking solution.
bool usingIndexToSort = false;
for (size_t i = 0; i < out->size(); ++i) {
QuerySolution* soln = (*out)[i];
if (!soln->hasBlockingStage) {
usingIndexToSort = true;
break;
}
}
if (!usingIndexToSort) {
for (size_t i = 0; i < params.indices.size(); ++i) {
const IndexEntry& index = params.indices[i];
// Only regular (non-plugin) indexes can be used to provide a sort, and only
// non-sparse indexes can be used to provide a sort.
//
// TODO: Sparse indexes can't normally provide a sort, because non-indexed
// documents could potentially be missing from the result set. However, if the
// query predicate can be used to guarantee that all documents to be returned
// are indexed, then the index should be able to provide the sort.
//
// For example:
// - Sparse index {a: 1, b: 1} should be able to provide a sort for
// find({b: 1}).sort({a: 1}). SERVER-13908.
// - Index {a: 1, b: "2dsphere"} (which is "geo-sparse", if
// 2dsphereIndexVersion=2) should be able to provide a sort for
// find({b: GEO}).sort({a:1}). SERVER-10801.
if (index.type != INDEX_BTREE) {
continue;
}
if (index.sparse) {
continue;
}
// Partial indexes can only be used to provide a sort only if the query predicate is
// compatible.
if (index.filterExpr && !expression::isSubsetOf(query.root(), index.filterExpr)) {
continue;
}
const BSONObj kp = QueryPlannerAnalysis::getSortPattern(index.keyPattern);
if (providesSort(query, kp)) {
LOG(5) << "Planner: outputting soln that uses index to provide sort." << endl;
QuerySolution* soln = buildWholeIXSoln(params.indices[i], query, params);
if (NULL != soln) {
PlanCacheIndexTree* indexTree = new PlanCacheIndexTree();
indexTree->setIndexEntry(params.indices[i]);
SolutionCacheData* scd = new SolutionCacheData();
scd->tree.reset(indexTree);
scd->solnType = SolutionCacheData::WHOLE_IXSCAN_SOLN;
scd->wholeIXSolnDir = 1;
soln->cacheData.reset(scd);
out->push_back(soln);
break;
}
}
if (providesSort(query, QueryPlannerCommon::reverseSortObj(kp))) {
LOG(5) << "Planner: outputting soln that uses (reverse) index "
<< "to provide sort." << endl;
QuerySolution* soln = buildWholeIXSoln(params.indices[i], query, params, -1);
if (NULL != soln) {
PlanCacheIndexTree* indexTree = new PlanCacheIndexTree();
indexTree->setIndexEntry(params.indices[i]);
SolutionCacheData* scd = new SolutionCacheData();
scd->tree.reset(indexTree);
scd->solnType = SolutionCacheData::WHOLE_IXSCAN_SOLN;
scd->wholeIXSolnDir = -1;
soln->cacheData.reset(scd);
out->push_back(soln);
break;
}
}
}
}
}
// geoNear and text queries *require* an index.
// Also, if a hint is specified it indicates that we MUST use it.
bool possibleToCollscan =
!QueryPlannerCommon::hasNode(query.root(), MatchExpression::GEO_NEAR) &&
!QueryPlannerCommon::hasNode(query.root(), MatchExpression::TEXT) && hintIndex.isEmpty();
// The caller can explicitly ask for a collscan.
bool collscanRequested = (params.options & QueryPlannerParams::INCLUDE_COLLSCAN);
// No indexed plans? We must provide a collscan if possible or else we can't run the query.
bool collscanNeeded = (0 == out->size() && canTableScan);
if (possibleToCollscan && (collscanRequested || collscanNeeded)) {
QuerySolution* collscan = buildCollscanSoln(query, false, params);
if (NULL != collscan) {
SolutionCacheData* scd = new SolutionCacheData();
scd->solnType = SolutionCacheData::COLLSCAN_SOLN;
collscan->cacheData.reset(scd);
out->push_back(collscan);
LOG(5) << "Planner: outputting a collscan:" << endl
<< collscan->toString();
}
}
return Status::OK();
}
// static
void QueryPlanner::plan(const CanonicalQuery& query,
const QueryPlannerParams& params,
vector<QuerySolution*>* out) {
QLOG() << "=============================\n"
<< "Beginning planning, options = " << optionString(params.options) << endl
<< "Canonical query:\n" << query.toString() << endl
<< "============================="
<< endl;
// The shortcut formerly known as IDHACK. See if it's a simple _id query. If so we might
// just make an ixscan over the _id index and bypass the rest of planning entirely.
if (!query.getParsed().isExplain() && !query.getParsed().showDiskLoc()
&& isSimpleIdQuery(query.getParsed().getFilter())
&& !query.getParsed().hasOption(QueryOption_CursorTailable)) {
// See if we can find an _id index.
for (size_t i = 0; i < params.indices.size(); ++i) {
if (isIdIndex(params.indices[i].keyPattern)) {
const IndexEntry& index = params.indices[i];
QLOG() << "IDHACK using index " << index.toString() << endl;
// If so, we make a simple scan to find the doc.
IndexScanNode* isn = new IndexScanNode();
isn->indexKeyPattern = index.keyPattern;
isn->indexIsMultiKey = index.multikey;
isn->direction = 1;
isn->bounds.isSimpleRange = true;
BSONObj key = getKeyFromQuery(index.keyPattern, query.getParsed().getFilter());
isn->bounds.startKey = isn->bounds.endKey = key;
isn->bounds.endKeyInclusive = true;
isn->computeProperties();
QuerySolution* soln = QueryPlannerAnalysis::analyzeDataAccess(query, params, isn);
if (NULL != soln) {
out->push_back(soln);
QLOG() << "IDHACK solution is:\n" << (*out)[0]->toString() << endl;
// And that's it.
return;
}
}
}
}
for (size_t i = 0; i < params.indices.size(); ++i) {
QLOG() << "idx " << i << " is " << params.indices[i].toString() << endl;
}
bool canTableScan = !(params.options & QueryPlannerParams::NO_TABLE_SCAN);
// If the query requests a tailable cursor, the only solution is a collscan + filter with
// tailable set on the collscan. TODO: This is a policy departure. Previously I think you
// could ask for a tailable cursor and it just tried to give you one. Now, we fail if we
// can't provide one. Is this what we want?
if (query.getParsed().hasOption(QueryOption_CursorTailable)) {
if (!QueryPlannerCommon::hasNode(query.root(), MatchExpression::GEO_NEAR)
&& canTableScan) {
QuerySolution* soln = buildCollscanSoln(query, true, params);
if (NULL != soln) {
out->push_back(soln);
}
}
return;
}
// The hint can be $natural: 1. If this happens, output a collscan. It's a weird way of
// saying "table scan for two, please."
if (!query.getParsed().getHint().isEmpty()) {
BSONElement natural = query.getParsed().getHint().getFieldDotted("$natural");
if (!natural.eoo()) {
QLOG() << "forcing a table scan due to hinted $natural\n";
if (canTableScan) {
QuerySolution* soln = buildCollscanSoln(query, false, params);
if (NULL != soln) {
out->push_back(soln);
}
}
return;
}
}
// NOR and NOT we can't handle well with indices. If we see them here, they weren't
// rewritten to remove the negation. Just output a collscan for those.
if (QueryPlannerCommon::hasNode(query.root(), MatchExpression::NOT)
|| QueryPlannerCommon::hasNode(query.root(), MatchExpression::NOR)) {
// If there's a near predicate, we can't handle this.
// TODO: Should canonicalized query detect this?
if (QueryPlannerCommon::hasNode(query.root(), MatchExpression::GEO_NEAR)) {
warning() << "Can't handle NOT/NOR with GEO_NEAR";
return;
}
QLOG() << "NOT/NOR in plan, just outtping a collscan\n";
if (canTableScan) {
QuerySolution* soln = buildCollscanSoln(query, false, params);
if (NULL != soln) {
out->push_back(soln);
}
}
return;
}
// Figure out what fields we care about.
unordered_set<string> fields;
QueryPlannerIXSelect::getFields(query.root(), "", &fields);
for (unordered_set<string>::const_iterator it = fields.begin(); it != fields.end(); ++it) {
QLOG() << "predicate over field " << *it << endl;
}
// Filter our indices so we only look at indices that are over our predicates.
vector<IndexEntry> relevantIndices;
// Hints require us to only consider the hinted index.
BSONObj hintIndex = query.getParsed().getHint();
// Snapshot is a form of a hint. If snapshot is set, try to use _id index to make a real
// plan. If that fails, just scan the _id index.
if (query.getParsed().isSnapshot()) {
// Find the ID index in indexKeyPatterns. It's our hint.
for (size_t i = 0; i < params.indices.size(); ++i) {
if (isIdIndex(params.indices[i].keyPattern)) {
hintIndex = params.indices[i].keyPattern;
break;
}
}
}
size_t hintIndexNumber = numeric_limits<size_t>::max();
if (!hintIndex.isEmpty()) {
// Sigh. If the hint is specified it might be using the index name.
BSONElement firstHintElt = hintIndex.firstElement();
if (str::equals("$hint", firstHintElt.fieldName()) && String == firstHintElt.type()) {
string hintName = firstHintElt.String();
for (size_t i = 0; i < params.indices.size(); ++i) {
if (params.indices[i].name == hintName) {
QLOG() << "hint by name specified, restricting indices to "
<< params.indices[i].keyPattern.toString() << endl;
relevantIndices.clear();
relevantIndices.push_back(params.indices[i]);
hintIndexNumber = i;
hintIndex = params.indices[i].keyPattern;
break;
}
}
}
else {
for (size_t i = 0; i < params.indices.size(); ++i) {
if (0 == params.indices[i].keyPattern.woCompare(hintIndex)) {
relevantIndices.clear();
relevantIndices.push_back(params.indices[i]);
QLOG() << "hint specified, restricting indices to " << hintIndex.toString()
<< endl;
hintIndexNumber = i;
break;
}
}
}
if (hintIndexNumber == numeric_limits<size_t>::max()) {
// This is supposed to be an error.
warning() << "Can't find hint for " << hintIndex.toString();
return;
}
}
else {
QLOG() << "Finding relevant indices\n";
QueryPlannerIXSelect::findRelevantIndices(fields, params.indices, &relevantIndices);
}
for (size_t i = 0; i < relevantIndices.size(); ++i) {
QLOG() << "relevant idx " << i << " is " << relevantIndices[i].toString() << endl;
}
// Figure out how useful each index is to each predicate.
// query.root() is now annotated with RelevantTag(s).
QueryPlannerIXSelect::rateIndices(query.root(), "", relevantIndices);
QLOG() << "rated tree" << endl;
QLOG() << query.root()->toString() << endl;
// If there is a GEO_NEAR it must have an index it can use directly.
// XXX: move into data access?
MatchExpression* gnNode = NULL;
if (QueryPlannerCommon::hasNode(query.root(), MatchExpression::GEO_NEAR, &gnNode)) {
// No index for GEO_NEAR? No query.
RelevantTag* tag = static_cast<RelevantTag*>(gnNode->getTag());
if (0 == tag->first.size() && 0 == tag->notFirst.size()) {
return;
}
GeoNearMatchExpression* gnme = static_cast<GeoNearMatchExpression*>(gnNode);
vector<size_t> newFirst;
// 2d + GEO_NEAR is annoying. Because 2d's GEO_NEAR isn't streaming we have to embed
// the full query tree inside it as a matcher.
for (size_t i = 0; i < tag->first.size(); ++i) {
// GEO_NEAR has a non-2d index it can use. We can deal w/that in normal planning.
if (!is2DIndex(relevantIndices[tag->first[i]].keyPattern)) {
newFirst.push_back(i);
continue;
}
// If we're here, GEO_NEAR has a 2d index. We create a 2dgeonear plan with the
// entire tree as a filter, if possible.
GeoNear2DNode* solnRoot = new GeoNear2DNode();
solnRoot->nq = gnme->getData();
if (MatchExpression::GEO_NEAR != query.root()->matchType()) {
// root is an AND, clone and delete the GEO_NEAR child.
MatchExpression* filterTree = query.root()->shallowClone();
verify(MatchExpression::AND == filterTree->matchType());
bool foundChild = false;
for (size_t i = 0; i < filterTree->numChildren(); ++i) {
if (MatchExpression::GEO_NEAR == filterTree->getChild(i)->matchType()) {
foundChild = true;
filterTree->getChildVector()->erase(filterTree->getChildVector()->begin() + i);
break;
}
}
verify(foundChild);
solnRoot->filter.reset(filterTree);
}
solnRoot->numWanted = query.getParsed().getNumToReturn();
if (0 == solnRoot->numWanted) {
solnRoot->numWanted = 100;
}
solnRoot->indexKeyPattern = relevantIndices[tag->first[i]].keyPattern;
// Remove the 2d index. 2d can only be the first field, and we know there is
// only one GEO_NEAR, so we don't care if anyone else was assigned it; it'll
// only be first for gnNode.
tag->first.erase(tag->first.begin() + i);
QuerySolution* soln = QueryPlannerAnalysis::analyzeDataAccess(query, params, solnRoot);
if (NULL != soln) {
out->push_back(soln);
}
}
// Continue planning w/non-2d indices tagged for this pred.
tag->first.swap(newFirst);
if (0 == tag->first.size() && 0 == tag->notFirst.size()) {
return;
}
}
// Likewise, if there is a TEXT it must have an index it can use directly.
MatchExpression* textNode;
if (QueryPlannerCommon::hasNode(query.root(), MatchExpression::TEXT, &textNode)) {
RelevantTag* tag = static_cast<RelevantTag*>(textNode->getTag());
if (0 == tag->first.size() && 0 == tag->notFirst.size()) {
return;
}
}
// If we have any relevant indices, we try to create indexed plans.
if (0 < relevantIndices.size()) {
// The enumerator spits out trees tagged with IndexTag(s).
PlanEnumerator isp(query.root(), &relevantIndices);
isp.init();
MatchExpression* rawTree;
while (isp.getNext(&rawTree)) {
QLOG() << "about to build solntree from tagged tree:\n" << rawTree->toString()
<< endl;
// This can fail if enumeration makes a mistake.
QuerySolutionNode* solnRoot =
QueryPlannerAccess::buildIndexedDataAccess(query, rawTree, false, relevantIndices);
if (NULL == solnRoot) { continue; }
QuerySolution* soln = QueryPlannerAnalysis::analyzeDataAccess(query, params, solnRoot);
if (NULL != soln) {
QLOG() << "Planner: adding solution:\n" << soln->toString() << endl;
out->push_back(soln);
}
}
}
QLOG() << "Planner: outputted " << out->size() << " indexed solutions.\n";
// An index was hinted. If there are any solutions, they use the hinted index. If not, we
// scan the entire index to provide results and output that as our plan. This is the
// desired behavior when an index is hinted that is not relevant to the query.
if (!hintIndex.isEmpty() && (0 == out->size())) {
QuerySolution* soln = buildWholeIXSoln(params.indices[hintIndexNumber], query, params);
if (NULL != soln) {
QLOG() << "Planner: outputting soln that uses hinted index as scan." << endl;
out->push_back(soln);
}
return;
}
// If a sort order is requested, there may be an index that provides it, even if that
// index is not over any predicates in the query.
//
// XXX XXX: Can we do this even if the index is sparse? Might we miss things?
if (!query.getParsed().getSort().isEmpty()
&& !QueryPlannerCommon::hasNode(query.root(), MatchExpression::GEO_NEAR)
&& !QueryPlannerCommon::hasNode(query.root(), MatchExpression::TEXT)) {
// See if we have a sort provided from an index already.
bool usingIndexToSort = false;
for (size_t i = 0; i < out->size(); ++i) {
QuerySolution* soln = (*out)[i];
if (!soln->hasSortStage) {
usingIndexToSort = true;
break;
}
}
if (!usingIndexToSort) {
for (size_t i = 0; i < params.indices.size(); ++i) {
const BSONObj& kp = params.indices[i].keyPattern;
if (providesSort(query, kp)) {
QLOG() << "Planner: outputting soln that uses index to provide sort."
<< endl;
QuerySolution* soln = buildWholeIXSoln(params.indices[i], query, params);
if (NULL != soln) {
out->push_back(soln);
break;
}
}
if (providesSort(query, QueryPlannerCommon::reverseSortObj(kp))) {
QLOG() << "Planner: outputting soln that uses (reverse) index "
<< "to provide sort." << endl;
QuerySolution* soln = buildWholeIXSoln(params.indices[i], query, params, -1);
if (NULL != soln) {
out->push_back(soln);
break;
}
}
}
}
}
// TODO: Do we always want to offer a collscan solution?
// XXX: currently disabling the always-use-a-collscan in order to find more planner bugs.
if ( !QueryPlannerCommon::hasNode(query.root(), MatchExpression::GEO_NEAR)
&& !QueryPlannerCommon::hasNode(query.root(), MatchExpression::TEXT)
&& ((params.options & QueryPlannerParams::INCLUDE_COLLSCAN) || (0 == out->size() && canTableScan)))
{
QuerySolution* collscan = buildCollscanSoln(query, false, params);
if (NULL != collscan) {
out->push_back(collscan);
QLOG() << "Planner: outputting a collscan:\n";
QLOG() << collscan->toString() << endl;
}
}
}
bool SubplanRunner::runSubplans() {
// This is what we annotate with the index selections and then turn into a solution.
auto_ptr<OrMatchExpression> theOr(
static_cast<OrMatchExpression*>(_query->root()->shallowClone()));
// This is the skeleton of index selections that is inserted into the cache.
auto_ptr<PlanCacheIndexTree> cacheData(new PlanCacheIndexTree());
for (size_t i = 0; i < theOr->numChildren(); ++i) {
MatchExpression* orChild = theOr->getChild(i);
auto_ptr<CanonicalQuery> orChildCQ(_cqs.front());
_cqs.pop();
// 'solutions' is owned by the SubplanRunner instance until
// it is popped from the queue.
vector<QuerySolution*> solutions = _solutions.front();
_solutions.pop();
// We already checked for zero solutions in planSubqueries(...).
invariant(!solutions.empty());
if (1 == solutions.size()) {
// There is only one solution. Transfer ownership to an auto_ptr.
auto_ptr<QuerySolution> autoSoln(solutions[0]);
// We want a well-formed *indexed* solution.
if (NULL == autoSoln->cacheData.get()) {
// For example, we don't cache things for 2d indices.
QLOG() << "Subplanner: No cache data for subchild " << orChild->toString();
return false;
}
if (SolutionCacheData::USE_INDEX_TAGS_SOLN != autoSoln->cacheData->solnType) {
QLOG() << "Subplanner: No indexed cache data for subchild "
<< orChild->toString();
return false;
}
// Add the index assignments to our original query.
Status tagStatus = QueryPlanner::tagAccordingToCache(
orChild, autoSoln->cacheData->tree.get(), _indexMap);
if (!tagStatus.isOK()) {
QLOG() << "Subplanner: Failed to extract indices from subchild "
<< orChild->toString();
return false;
}
// Add the child's cache data to the cache data we're creating for the main query.
cacheData->children.push_back(autoSoln->cacheData->tree->clone());
}
else {
// N solutions, rank them. Takes ownership of orChildCQ.
// the working set will be shared by the candidate plans and owned by the runner
WorkingSet* sharedWorkingSet = new WorkingSet();
MultiPlanStage* multiPlanStage = new MultiPlanStage(_collection,
orChildCQ.get());
// Dump all the solutions into the MPR.
for (size_t ix = 0; ix < solutions.size(); ++ix) {
PlanStage* nextPlanRoot;
verify(StageBuilder::build(_txn,
_collection,
*solutions[ix],
sharedWorkingSet,
&nextPlanRoot));
// Owns first two arguments
multiPlanStage->addPlan(solutions[ix], nextPlanRoot, sharedWorkingSet);
}
multiPlanStage->pickBestPlan();
if (! multiPlanStage->bestPlanChosen()) {
QLOG() << "Subplanner: Failed to pick best plan for subchild "
<< orChildCQ->toString();
return false;
}
Runner* mpr = new SingleSolutionRunner(_collection,
orChildCQ.release(),
multiPlanStage->bestSolution(),
multiPlanStage,
sharedWorkingSet);
_underlyingRunner.reset(mpr);
if (_killed) {
QLOG() << "Subplanner: Killed while picking best plan for subchild "
<< orChild->toString();
return false;
}
QuerySolution* bestSoln = multiPlanStage->bestSolution();
if (SolutionCacheData::USE_INDEX_TAGS_SOLN != bestSoln->cacheData->solnType) {
QLOG() << "Subplanner: No indexed cache data for subchild "
<< orChild->toString();
return false;
}
// Add the index assignments to our original query.
Status tagStatus = QueryPlanner::tagAccordingToCache(
orChild, bestSoln->cacheData->tree.get(), _indexMap);
if (!tagStatus.isOK()) {
QLOG() << "Subplanner: Failed to extract indices from subchild "
<< orChild->toString();
return false;
}
cacheData->children.push_back(bestSoln->cacheData->tree->clone());
}
}
// Must do this before using the planner functionality.
sortUsingTags(theOr.get());
// Use the cached index assignments to build solnRoot. Takes ownership of 'theOr'
QuerySolutionNode* solnRoot = QueryPlannerAccess::buildIndexedDataAccess(
*_query, theOr.release(), false, _plannerParams.indices);
if (NULL == solnRoot) {
QLOG() << "Subplanner: Failed to build indexed data path for subplanned query\n";
return false;
}
QLOG() << "Subplanner: fully tagged tree is " << solnRoot->toString();
// Takes ownership of 'solnRoot'
QuerySolution* soln = QueryPlannerAnalysis::analyzeDataAccess(*_query,
_plannerParams,
solnRoot);
if (NULL == soln) {
QLOG() << "Subplanner: Failed to analyze subplanned query";
return false;
}
// We want our franken-solution to be cached.
SolutionCacheData* scd = new SolutionCacheData();
scd->tree.reset(cacheData.release());
soln->cacheData.reset(scd);
QLOG() << "Subplanner: Composite solution is " << soln->toString() << endl;
// We use one of these even if there is one plan. We do this so that the entry is cached
// with stats obtained in the same fashion as a competitive ranking would have obtained
// them.
MultiPlanStage* multiPlanStage = new MultiPlanStage(_collection, _query.get());
WorkingSet* ws = new WorkingSet();
PlanStage* root;
verify(StageBuilder::build(_txn, _collection, *soln, ws, &root));
multiPlanStage->addPlan(soln, root, ws); // Takes ownership first two arguments.
multiPlanStage->pickBestPlan();
if (! multiPlanStage->bestPlanChosen()) {
QLOG() << "Subplanner: Failed to pick best plan for subchild "
<< _query->toString();
return false;
}
Runner* mpr = new SingleSolutionRunner(_collection,
_query.release(),
multiPlanStage->bestSolution(),
multiPlanStage,
ws);
_underlyingRunner.reset(mpr);
return true;
}
Status SubplanStage::planSubqueries() {
_orExpression = _query->root()->shallowClone();
if (isContainedOr(_orExpression.get())) {
_orExpression = rewriteToRootedOr(std::move(_orExpression));
invariant(CanonicalQuery::isValid(_orExpression.get(), _query->getParsed()).isOK());
}
for (size_t i = 0; i < _plannerParams.indices.size(); ++i) {
const IndexEntry& ie = _plannerParams.indices[i];
_indexMap[ie.keyPattern] = i;
LOG(5) << "Subplanner: index " << i << " is " << ie.toString();
}
const ExtensionsCallbackReal extensionsCallback(getOpCtx(), &_collection->ns());
for (size_t i = 0; i < _orExpression->numChildren(); ++i) {
// We need a place to shove the results from planning this branch.
_branchResults.push_back(new BranchPlanningResult());
BranchPlanningResult* branchResult = _branchResults.back();
MatchExpression* orChild = _orExpression->getChild(i);
// Turn the i-th child into its own query.
auto statusWithCQ = CanonicalQuery::canonicalize(*_query, orChild, extensionsCallback);
if (!statusWithCQ.isOK()) {
mongoutils::str::stream ss;
ss << "Can't canonicalize subchild " << orChild->toString() << " "
<< statusWithCQ.getStatus().reason();
return Status(ErrorCodes::BadValue, ss);
}
branchResult->canonicalQuery = std::move(statusWithCQ.getValue());
// Plan the i-th child. We might be able to find a plan for the i-th child in the plan
// cache. If there's no cached plan, then we generate and rank plans using the MPS.
CachedSolution* rawCS;
if (PlanCache::shouldCacheQuery(*branchResult->canonicalQuery) &&
_collection->infoCache()
->getPlanCache()
->get(*branchResult->canonicalQuery, &rawCS)
.isOK()) {
// We have a CachedSolution. Store it for later.
LOG(5) << "Subplanner: cached plan found for child " << i << " of "
<< _orExpression->numChildren();
branchResult->cachedSolution.reset(rawCS);
} else {
// No CachedSolution found. We'll have to plan from scratch.
LOG(5) << "Subplanner: planning child " << i << " of " << _orExpression->numChildren();
// We don't set NO_TABLE_SCAN because peeking at the cache data will keep us from
// considering any plan that's a collscan.
Status status = QueryPlanner::plan(*branchResult->canonicalQuery,
_plannerParams,
&branchResult->solutions.mutableVector());
if (!status.isOK()) {
mongoutils::str::stream ss;
ss << "Can't plan for subchild " << branchResult->canonicalQuery->toString() << " "
<< status.reason();
return Status(ErrorCodes::BadValue, ss);
}
LOG(5) << "Subplanner: got " << branchResult->solutions.size() << " solutions";
if (0 == branchResult->solutions.size()) {
// If one child doesn't have an indexed solution, bail out.
mongoutils::str::stream ss;
ss << "No solutions for subchild " << branchResult->canonicalQuery->toString();
return Status(ErrorCodes::BadValue, ss);
}
}
}
return Status::OK();
}
// static
Status QueryPlanner::plan(const CanonicalQuery& query,
const QueryPlannerParams& params,
std::vector<QuerySolution*>* out) {
QLOG() << "=============================\n"
<< "Beginning planning, options = " << optionString(params.options) << endl
<< "Canonical query:\n" << query.toString() << endl
<< "============================="
<< endl;
for (size_t i = 0; i < params.indices.size(); ++i) {
QLOG() << "idx " << i << " is " << params.indices[i].toString() << endl;
}
bool canTableScan = !(params.options & QueryPlannerParams::NO_TABLE_SCAN);
// If the query requests a tailable cursor, the only solution is a collscan + filter with
// tailable set on the collscan. TODO: This is a policy departure. Previously I think you
// could ask for a tailable cursor and it just tried to give you one. Now, we fail if we
// can't provide one. Is this what we want?
if (query.getParsed().hasOption(QueryOption_CursorTailable)) {
if (!QueryPlannerCommon::hasNode(query.root(), MatchExpression::GEO_NEAR)
&& canTableScan) {
QuerySolution* soln = buildCollscanSoln(query, true, params);
if (NULL != soln) {
out->push_back(soln);
}
}
return Status::OK();
}
// The hint can be $natural: 1. If this happens, output a collscan. It's a weird way of
// saying "table scan for two, please."
if (!query.getParsed().getHint().isEmpty()) {
BSONElement natural = query.getParsed().getHint().getFieldDotted("$natural");
if (!natural.eoo()) {
QLOG() << "forcing a table scan due to hinted $natural\n";
// min/max are incompatible with $natural.
if (canTableScan && query.getParsed().getMin().isEmpty()
&& query.getParsed().getMax().isEmpty()) {
QuerySolution* soln = buildCollscanSoln(query, false, params);
if (NULL != soln) {
out->push_back(soln);
}
}
return Status::OK();
}
}
// Figure out what fields we care about.
unordered_set<string> fields;
QueryPlannerIXSelect::getFields(query.root(), "", &fields);
for (unordered_set<string>::const_iterator it = fields.begin(); it != fields.end(); ++it) {
QLOG() << "predicate over field " << *it << endl;
}
// Filter our indices so we only look at indices that are over our predicates.
vector<IndexEntry> relevantIndices;
// Hints require us to only consider the hinted index.
BSONObj hintIndex = query.getParsed().getHint();
// Snapshot is a form of a hint. If snapshot is set, try to use _id index to make a real
// plan. If that fails, just scan the _id index.
if (query.getParsed().isSnapshot()) {
// Find the ID index in indexKeyPatterns. It's our hint.
for (size_t i = 0; i < params.indices.size(); ++i) {
if (isIdIndex(params.indices[i].keyPattern)) {
hintIndex = params.indices[i].keyPattern;
break;
}
}
}
size_t hintIndexNumber = numeric_limits<size_t>::max();
if (hintIndex.isEmpty()) {
QueryPlannerIXSelect::findRelevantIndices(fields, params.indices, &relevantIndices);
}
else {
// Sigh. If the hint is specified it might be using the index name.
BSONElement firstHintElt = hintIndex.firstElement();
if (str::equals("$hint", firstHintElt.fieldName()) && String == firstHintElt.type()) {
string hintName = firstHintElt.String();
for (size_t i = 0; i < params.indices.size(); ++i) {
if (params.indices[i].name == hintName) {
QLOG() << "hint by name specified, restricting indices to "
<< params.indices[i].keyPattern.toString() << endl;
relevantIndices.clear();
relevantIndices.push_back(params.indices[i]);
hintIndexNumber = i;
hintIndex = params.indices[i].keyPattern;
break;
}
}
}
else {
for (size_t i = 0; i < params.indices.size(); ++i) {
if (0 == params.indices[i].keyPattern.woCompare(hintIndex)) {
relevantIndices.clear();
relevantIndices.push_back(params.indices[i]);
QLOG() << "hint specified, restricting indices to " << hintIndex.toString()
<< endl;
hintIndexNumber = i;
break;
}
}
}
if (hintIndexNumber == numeric_limits<size_t>::max()) {
return Status(ErrorCodes::BadValue, "bad hint");
}
}
// Deal with the .min() and .max() query options. If either exist we can only use an index
// that matches the object inside.
if (!query.getParsed().getMin().isEmpty() || !query.getParsed().getMax().isEmpty()) {
BSONObj minObj = query.getParsed().getMin();
BSONObj maxObj = query.getParsed().getMax();
// This is the index into params.indices[...] that we use.
size_t idxNo = numeric_limits<size_t>::max();
// If there's an index hinted we need to be able to use it.
if (!hintIndex.isEmpty()) {
if (!minObj.isEmpty() && !indexCompatibleMaxMin(minObj, hintIndex)) {
QLOG() << "minobj doesnt work w hint";
return Status(ErrorCodes::BadValue,
"hint provided does not work with min query");
}
if (!maxObj.isEmpty() && !indexCompatibleMaxMin(maxObj, hintIndex)) {
QLOG() << "maxobj doesnt work w hint";
return Status(ErrorCodes::BadValue,
"hint provided does not work with max query");
}
idxNo = hintIndexNumber;
}
else {
// No hinted index, look for one that is compatible (has same field names and
// ordering thereof).
for (size_t i = 0; i < params.indices.size(); ++i) {
const BSONObj& kp = params.indices[i].keyPattern;
BSONObj toUse = minObj.isEmpty() ? maxObj : minObj;
if (indexCompatibleMaxMin(toUse, kp)) {
idxNo = i;
break;
}
}
}
if (idxNo == numeric_limits<size_t>::max()) {
QLOG() << "Can't find relevant index to use for max/min query";
// Can't find an index to use, bail out.
return Status(ErrorCodes::BadValue,
"unable to find relevant index for max/min query");
}
// maxObj can be empty; the index scan just goes until the end. minObj can't be empty
// though, so if it is, we make a minKey object.
if (minObj.isEmpty()) {
BSONObjBuilder bob;
bob.appendMinKey("");
minObj = bob.obj();
}
else {
// Must strip off the field names to make an index key.
minObj = stripFieldNames(minObj);
}
if (!maxObj.isEmpty()) {
// Must strip off the field names to make an index key.
maxObj = stripFieldNames(maxObj);
}
QLOG() << "max/min query using index " << params.indices[idxNo].toString() << endl;
// Make our scan and output.
QuerySolutionNode* solnRoot = QueryPlannerAccess::makeIndexScan(params.indices[idxNo],
query,
params,
minObj,
maxObj);
QuerySolution* soln = QueryPlannerAnalysis::analyzeDataAccess(query, params, solnRoot);
if (NULL != soln) {
out->push_back(soln);
}
return Status::OK();
}
for (size_t i = 0; i < relevantIndices.size(); ++i) {
QLOG() << "relevant idx " << i << " is " << relevantIndices[i].toString() << endl;
}
// Figure out how useful each index is to each predicate.
// query.root() is now annotated with RelevantTag(s).
QueryPlannerIXSelect::rateIndices(query.root(), "", relevantIndices);
QLOG() << "rated tree" << endl;
QLOG() << query.root()->toString() << endl;
// If there is a GEO_NEAR it must have an index it can use directly.
// XXX: move into data access?
MatchExpression* gnNode = NULL;
if (QueryPlannerCommon::hasNode(query.root(), MatchExpression::GEO_NEAR, &gnNode)) {
// No index for GEO_NEAR? No query.
RelevantTag* tag = static_cast<RelevantTag*>(gnNode->getTag());
if (0 == tag->first.size() && 0 == tag->notFirst.size()) {
QLOG() << "unable to find index for $geoNear query" << endl;
return Status(ErrorCodes::BadValue, "unable to find index for $geoNear query");
}
GeoNearMatchExpression* gnme = static_cast<GeoNearMatchExpression*>(gnNode);
vector<size_t> newFirst;
// 2d + GEO_NEAR is annoying. Because 2d's GEO_NEAR isn't streaming we have to embed
// the full query tree inside it as a matcher.
for (size_t i = 0; i < tag->first.size(); ++i) {
// GEO_NEAR has a non-2d index it can use. We can deal w/that in normal planning.
if (!is2DIndex(relevantIndices[tag->first[i]].keyPattern)) {
newFirst.push_back(i);
continue;
}
// If we're here, GEO_NEAR has a 2d index. We create a 2dgeonear plan with the
// entire tree as a filter, if possible.
GeoNear2DNode* solnRoot = new GeoNear2DNode();
solnRoot->nq = gnme->getData();
if (NULL != query.getProj()) {
solnRoot->addPointMeta = query.getProj()->wantGeoNearPoint();
solnRoot->addDistMeta = query.getProj()->wantGeoNearDistance();
}
if (MatchExpression::GEO_NEAR != query.root()->matchType()) {
// root is an AND, clone and delete the GEO_NEAR child.
MatchExpression* filterTree = query.root()->shallowClone();
verify(MatchExpression::AND == filterTree->matchType());
bool foundChild = false;
for (size_t i = 0; i < filterTree->numChildren(); ++i) {
if (MatchExpression::GEO_NEAR == filterTree->getChild(i)->matchType()) {
foundChild = true;
filterTree->getChildVector()->erase(filterTree->getChildVector()->begin() + i);
break;
}
}
verify(foundChild);
solnRoot->filter.reset(filterTree);
}
solnRoot->numWanted = query.getParsed().getNumToReturn();
if (0 == solnRoot->numWanted) {
solnRoot->numWanted = 100;
}
solnRoot->indexKeyPattern = relevantIndices[tag->first[i]].keyPattern;
// Remove the 2d index. 2d can only be the first field, and we know there is
// only one GEO_NEAR, so we don't care if anyone else was assigned it; it'll
// only be first for gnNode.
tag->first.erase(tag->first.begin() + i);
QuerySolution* soln = QueryPlannerAnalysis::analyzeDataAccess(query, params, solnRoot);
if (NULL != soln) {
out->push_back(soln);
}
}
// Continue planning w/non-2d indices tagged for this pred.
tag->first.swap(newFirst);
if (0 == tag->first.size() && 0 == tag->notFirst.size()) {
return Status::OK();
}
}
// Likewise, if there is a TEXT it must have an index it can use directly.
MatchExpression* textNode;
if (QueryPlannerCommon::hasNode(query.root(), MatchExpression::TEXT, &textNode)) {
RelevantTag* tag = static_cast<RelevantTag*>(textNode->getTag());
if (0 == tag->first.size() && 0 == tag->notFirst.size()) {
return Status::OK();
}
}
// If we have any relevant indices, we try to create indexed plans.
if (0 < relevantIndices.size()) {
// The enumerator spits out trees tagged with IndexTag(s).
PlanEnumeratorParams enumParams;
enumParams.intersect = params.options & QueryPlannerParams::INDEX_INTERSECTION;
enumParams.root = query.root();
enumParams.indices = &relevantIndices;
PlanEnumerator isp(enumParams);
isp.init();
MatchExpression* rawTree;
// XXX: have limit on # of indexed solns we'll consider. We could have a perverse
// query and index that could make n^2 very unpleasant.
while (isp.getNext(&rawTree)) {
QLOG() << "about to build solntree from tagged tree:\n" << rawTree->toString()
<< endl;
// This can fail if enumeration makes a mistake.
QuerySolutionNode* solnRoot =
QueryPlannerAccess::buildIndexedDataAccess(query, rawTree, false, relevantIndices);
if (NULL == solnRoot) { continue; }
QuerySolution* soln = QueryPlannerAnalysis::analyzeDataAccess(query, params, solnRoot);
if (NULL != soln) {
QLOG() << "Planner: adding solution:\n" << soln->toString() << endl;
out->push_back(soln);
}
}
}
QLOG() << "Planner: outputted " << out->size() << " indexed solutions.\n";
// An index was hinted. If there are any solutions, they use the hinted index. If not, we
// scan the entire index to provide results and output that as our plan. This is the
// desired behavior when an index is hinted that is not relevant to the query.
if (!hintIndex.isEmpty()) {
if (0 == out->size()) {
QuerySolution* soln = buildWholeIXSoln(params.indices[hintIndexNumber], query, params);
verify(NULL != soln);
QLOG() << "Planner: outputting soln that uses hinted index as scan." << endl;
out->push_back(soln);
}
return Status::OK();
}
// If a sort order is requested, there may be an index that provides it, even if that
// index is not over any predicates in the query.
//
if (!query.getParsed().getSort().isEmpty()
&& !QueryPlannerCommon::hasNode(query.root(), MatchExpression::GEO_NEAR)
&& !QueryPlannerCommon::hasNode(query.root(), MatchExpression::TEXT)) {
// See if we have a sort provided from an index already.
bool usingIndexToSort = false;
for (size_t i = 0; i < out->size(); ++i) {
QuerySolution* soln = (*out)[i];
if (!soln->hasSortStage) {
usingIndexToSort = true;
break;
}
}
if (!usingIndexToSort) {
for (size_t i = 0; i < params.indices.size(); ++i) {
const IndexEntry& index = params.indices[i];
if (index.sparse) {
continue;
}
const BSONObj kp = LiteParsedQuery::normalizeSortOrder(index.keyPattern);
if (providesSort(query, kp)) {
QLOG() << "Planner: outputting soln that uses index to provide sort."
<< endl;
QuerySolution* soln = buildWholeIXSoln(params.indices[i], query, params);
if (NULL != soln) {
out->push_back(soln);
break;
}
}
if (providesSort(query, QueryPlannerCommon::reverseSortObj(kp))) {
QLOG() << "Planner: outputting soln that uses (reverse) index "
<< "to provide sort." << endl;
QuerySolution* soln = buildWholeIXSoln(params.indices[i], query, params, -1);
if (NULL != soln) {
out->push_back(soln);
break;
}
}
}
}
}
// TODO: Do we always want to offer a collscan solution?
// XXX: currently disabling the always-use-a-collscan in order to find more planner bugs.
if ( !QueryPlannerCommon::hasNode(query.root(), MatchExpression::GEO_NEAR)
&& !QueryPlannerCommon::hasNode(query.root(), MatchExpression::TEXT)
&& hintIndex.isEmpty()
&& ((params.options & QueryPlannerParams::INCLUDE_COLLSCAN) || (0 == out->size() && canTableScan)))
{
QuerySolution* collscan = buildCollscanSoln(query, false, params);
if (NULL != collscan) {
out->push_back(collscan);
QLOG() << "Planner: outputting a collscan:\n";
QLOG() << collscan->toString() << endl;
}
}
return Status::OK();
}
// static
Status QueryPlanner::planFromCache(const CanonicalQuery& query,
const QueryPlannerParams& params,
const SolutionCacheData& cacheData,
QuerySolution** out) {
if (SolutionCacheData::WHOLE_IXSCAN_SOLN == cacheData.solnType) {
// The solution can be constructed by a scan over the entire index.
QuerySolution* soln = buildWholeIXSoln(*cacheData.tree->entry,
query,
params,
cacheData.wholeIXSolnDir);
if (soln == NULL) {
return Status(ErrorCodes::BadValue,
"plan cache error: soln that uses index to provide sort");
}
else {
*out = soln;
return Status::OK();
}
}
else if (SolutionCacheData::COLLSCAN_SOLN == cacheData.solnType) {
// The cached solution is a collection scan. We don't cache collscans
// with tailable==true, hence the false below.
QuerySolution* soln = buildCollscanSoln(query, false, params);
if (soln == NULL) {
return Status(ErrorCodes::BadValue, "plan cache error: collection scan soln");
}
else {
*out = soln;
return Status::OK();
}
}
// SolutionCacheData::USE_TAGS_SOLN == cacheData->solnType
// If we're here then this is neither the whole index scan or collection scan
// cases, and we proceed by using the PlanCacheIndexTree to tag the query tree.
// Create a copy of the expression tree. We use cachedSoln to annotate this with indices.
MatchExpression* clone = query.root()->shallowClone();
QLOG() << "Tagging the match expression according to cache data: " << endl
<< "Filter:" << endl << clone->toString()
<< "Cache data:" << endl << cacheData.toString();
// Map from index name to index number.
// TODO: can we assume that the index numbering has the same lifetime
// as the cache state?
map<BSONObj, size_t> indexMap;
for (size_t i = 0; i < params.indices.size(); ++i) {
const IndexEntry& ie = params.indices[i];
indexMap[ie.keyPattern] = i;
QLOG() << "Index " << i << ": " << ie.keyPattern.toString() << endl;
}
Status s = tagAccordingToCache(clone, cacheData.tree.get(), indexMap);
if (!s.isOK()) {
return s;
}
// The planner requires a defined sort order.
sortUsingTags(clone);
QLOG() << "Tagged tree:" << endl << clone->toString();
// Use the cached index assignments to build solnRoot. Takes ownership of clone.
QuerySolutionNode* solnRoot =
QueryPlannerAccess::buildIndexedDataAccess(query, clone, false, params.indices);
if (NULL != solnRoot) {
// Takes ownership of 'solnRoot'.
QuerySolution* soln = QueryPlannerAnalysis::analyzeDataAccess(query,
params,
solnRoot);
if (NULL != soln) {
QLOG() << "Planner: solution constructed from the cache:\n" << soln->toString() << endl;
*out = soln;
return Status::OK();
}
}
return Status(ErrorCodes::BadValue, "couldn't plan from cache");
}