// static
bool QueryPlannerIXSelect::compatible(const BSONElement& elt,
const IndexEntry& index,
MatchExpression* node) {
// Historically one could create indices with any particular value for the index spec,
// including values that now indicate a special index. As such we have to make sure the
// index type wasn't overridden before we pay attention to the string in the index key
// pattern element.
//
// e.g. long ago we could have created an index {a: "2dsphere"} and it would
// be treated as a btree index by an ancient version of MongoDB. To try to run
// 2dsphere queries over it would be folly.
string indexedFieldType;
if (String != elt.type() || (INDEX_BTREE == index.type)) {
indexedFieldType = "";
}
else {
indexedFieldType = elt.String();
}
// We know elt.fieldname() == node->path().
MatchExpression::MatchType exprtype = node->matchType();
if (indexedFieldType.empty()) {
// Can't check for null w/a sparse index.
if (exprtype == MatchExpression::EQ && index.sparse) {
const EqualityMatchExpression* expr
= static_cast<const EqualityMatchExpression*>(node);
if (expr->getData().isNull()) {
return false;
}
}
// We can't use a btree-indexed field for geo expressions.
if (exprtype == MatchExpression::GEO || exprtype == MatchExpression::GEO_NEAR) {
return false;
}
// There are restrictions on when we can use the index if
// the expression is a NOT.
if (exprtype == MatchExpression::NOT) {
// Prevent negated preds from using sparse or
// multikey indices. We do so for sparse indices because
// we will fail to return the documents which do not contain
// the indexed fields.
//
// We avoid multikey indices because of the semantics of
// negations on multikey fields. For example, with multikey
// index {a:1}, the document {a: [1,2,3]} does *not* match
// the query {a: {$ne: 3}}. We'd mess this up if we used
// an index scan over [MinKey, 3) and (3, MaxKey] without
// a filter.
if (index.sparse || index.multikey) {
return false;
}
// Can't index negations of MOD or REGEX
MatchExpression::MatchType childtype = node->getChild(0)->matchType();
if (MatchExpression::REGEX == childtype ||
MatchExpression::MOD == childtype) {
return false;
}
}
// We can only index EQ using text indices. This is an artificial limitation imposed by
// FTSSpec::getIndexPrefix() which will fail if there is not an EQ predicate on each
// index prefix field of the text index.
//
// Example for key pattern {a: 1, b: "text"}:
// - Allowed: node = {a: 7}
// - Not allowed: node = {a: {$gt: 7}}
if (INDEX_TEXT != index.type) {
return true;
}
// If we're here we know it's a text index. Equalities are OK anywhere in a text index.
if (MatchExpression::EQ == exprtype) {
return true;
}
// Not-equalities can only go in a suffix field of an index kp. We look through the key
// pattern to see if the field we're looking at now appears as a prefix. If so, we
// can't use this index for it.
BSONObjIterator specIt(index.keyPattern);
while (specIt.more()) {
BSONElement elt = specIt.next();
// We hit the dividing mark between prefix and suffix, so whatever field we're
// looking at is a suffix, since it appears *after* the dividing mark between the
// two. As such, we can use the index.
if (String == elt.type()) {
return true;
}
// If we're here, we're still looking at prefix elements. We know that exprtype
// isn't EQ so we can't use this index.
if (node->path() == elt.fieldNameStringData()) {
return false;
}
}
// NOTE: This shouldn't be reached. Text index implies there is a separator implies we
// will always hit the 'return true' above.
invariant(0);
return true;
}
else if (IndexNames::HASHED == indexedFieldType) {
return exprtype == MatchExpression::MATCH_IN || exprtype == MatchExpression::EQ;
}
else if (IndexNames::GEO_2DSPHERE == indexedFieldType) {
if (exprtype == MatchExpression::GEO) {
// within or intersect.
GeoMatchExpression* gme = static_cast<GeoMatchExpression*>(node);
const GeoQuery& gq = gme->getGeoQuery();
const GeometryContainer& gc = gq.getGeometry();
return gc.hasS2Region();
}
else if (exprtype == MatchExpression::GEO_NEAR) {
GeoNearMatchExpression* gnme = static_cast<GeoNearMatchExpression*>(node);
// Make sure the near query is compatible with 2dsphere.
if (gnme->getData().centroid.crs == SPHERE || gnme->getData().isNearSphere) {
return true;
}
}
return false;
}
else if (IndexNames::GEO_2D == indexedFieldType) {
if (exprtype == MatchExpression::GEO_NEAR) {
GeoNearMatchExpression* gnme = static_cast<GeoNearMatchExpression*>(node);
return gnme->getData().centroid.crs == FLAT;
}
else if (exprtype == MatchExpression::GEO) {
// 2d only supports within.
GeoMatchExpression* gme = static_cast<GeoMatchExpression*>(node);
const GeoQuery& gq = gme->getGeoQuery();
if (GeoQuery::WITHIN != gq.getPred()) {
return false;
}
const GeometryContainer& gc = gq.getGeometry();
// 2d indices answer flat queries.
if (gc.hasFlatRegion()) {
return true;
}
// 2d indices can answer centerSphere queries.
if (NULL == gc._cap.get()) {
return false;
}
verify(SPHERE == gc._cap->crs);
const Circle& circle = gc._cap->circle;
// No wrapping around the edge of the world is allowed in 2d centerSphere.
return twoDWontWrap(circle, index);
}
return false;
}
else if (IndexNames::TEXT == indexedFieldType) {
return (exprtype == MatchExpression::TEXT);
}
else if (IndexNames::GEO_HAYSTACK == indexedFieldType) {
return false;
}
else {
warning() << "Unknown indexing for node " << node->toString()
<< " and field " << elt.toString() << endl;
verify(0);
}
}
// static
bool QueryPlannerIXSelect::compatible(const BSONElement& elt,
const IndexEntry& index,
MatchExpression* node) {
// XXX: CatalogHack::getAccessMethodName: do we have to worry about this? when?
string ixtype;
if (String != elt.type()) {
ixtype = "";
}
else {
ixtype = elt.String();
}
// We know elt.fieldname() == node->path().
MatchExpression::MatchType exprtype = node->matchType();
// TODO: use indexnames
if ("" == ixtype) {
if (index.sparse && exprtype == MatchExpression::EQ) {
// Can't check for null w/a sparse index.
const EqualityMatchExpression* expr
= static_cast<const EqualityMatchExpression*>(node);
return !expr->getData().isNull();
}
return exprtype != MatchExpression::GEO && exprtype != MatchExpression::GEO_NEAR;
}
else if ("hashed" == ixtype) {
return exprtype == MatchExpression::MATCH_IN || exprtype == MatchExpression::EQ;
}
else if ("2dsphere" == ixtype) {
if (exprtype == MatchExpression::GEO) {
// within or intersect.
GeoMatchExpression* gme = static_cast<GeoMatchExpression*>(node);
const GeoQuery& gq = gme->getGeoQuery();
const GeometryContainer& gc = gq.getGeometry();
return gc.hasS2Region();
}
else if (exprtype == MatchExpression::GEO_NEAR) {
GeoNearMatchExpression* gnme = static_cast<GeoNearMatchExpression*>(node);
// Make sure the near query is compatible with 2dsphere.
if (gnme->getData().centroid.crs == SPHERE || gnme->getData().isNearSphere) {
return true;
}
}
return false;
}
else if ("2d" == ixtype) {
if (exprtype == MatchExpression::GEO_NEAR) {
GeoNearMatchExpression* gnme = static_cast<GeoNearMatchExpression*>(node);
return gnme->getData().centroid.crs == FLAT;
}
else if (exprtype == MatchExpression::GEO) {
// 2d only supports within.
GeoMatchExpression* gme = static_cast<GeoMatchExpression*>(node);
const GeoQuery& gq = gme->getGeoQuery();
if (GeoQuery::WITHIN != gq.getPred()) {
return false;
}
const GeometryContainer& gc = gq.getGeometry();
// 2d indices answer flat queries.
if (gc.hasFlatRegion()) {
return true;
}
// 2d indices can answer centerSphere queries.
if (NULL == gc._cap.get()) {
return false;
}
verify(SPHERE == gc._cap->crs);
const Circle& circle = gc._cap->circle;
// No wrapping around the edge of the world is allowed in 2d centerSphere.
return twoDWontWrap(circle, index);
}
return false;
}
else if ("text" == ixtype) {
return (exprtype == MatchExpression::TEXT);
}
else if ("geoHaystack" == ixtype) {
return false;
}
else {
warning() << "Unknown indexing for node " << node->toString()
<< " and field " << elt.toString() << endl;
verify(0);
}
}