void sortUsingTags(MatchExpression* tree) {
for (size_t i = 0; i < tree->numChildren(); ++i) {
sortUsingTags(tree->getChild(i));
}
std::vector<MatchExpression*>* children = tree->getChildVector();
if (NULL != children) {
std::sort(children->begin(), children->end(), TagComparison);
}
}
bool PlanEnumerator::getNext(MatchExpression** tree) {
if (_done) { return false; }
// Tag with our first solution.
tagMemo(_nodeToId[_root]);
*tree = _root->shallowClone();
tagForSort(*tree);
sortUsingTags(*tree);
_root->resetTag();
QLOG() << "Enumerator: memo right before moving:\n";
dumpMemo();
_done = nextMemo(_nodeToId[_root]);
QLOG() << "Enumerator: memo right after moving:\n";
dumpMemo();
return true;
}
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;
}
// 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");
}
