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Code Issues Releases Activity

Can pick index with more key specificity than required by sort / find spec

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This commit is contained in:
Aaron 2009-02-11 15:37:51 -05:00
parent 878cffc529
commit c326d4a508
4 changed files with 30 additions and 9 deletions
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12
db/jsobj.cpp
View File

@ -739,6 +739,13 @@ namespace mongo {
}
return b.done();
}
/**
sets element field names to empty string
If a field in pattern is missing, it is omitted from the returned
object. Unlike extractFieldsDotted, it does not return an empty
object on missing pattern field.
*/
BSONObj BSONObj::extractFieldsUnDotted(BSONObj pattern) const {
BSONObjBuilder b;
BSONObjIterator i(pattern);
@ -747,9 +754,8 @@ namespace mongo {
if ( e.eoo() )
break;
BSONElement x = getField(e.fieldName());
if ( x.eoo() )
return BSONObj();
b.appendAs(x, "");
if ( !x.eoo() )
b.appendAs(x, "");
}
return b.obj();
}

3
db/jsobj.h
View File

@ -566,6 +566,9 @@ namespace mongo {
/**
sets element field names to empty string
If a field in pattern is missing, it is omitted from the returned
object. Unlike extractFieldsDotted, it does not return an empty
object on missing pattern field.
*/
BSONObj extractFieldsUnDotted(BSONObj pattern) const;

20
db/query.cpp
View File

@ -58,11 +58,11 @@ namespace mongo {
while ( 1 ) {
BSONElement ie = i.next();
BSONElement se = s.next();
if ( ie.eoo() ) {
if ( !se.eoo() )
return 0;
if ( ie.eoo() && !se.eoo() )
return 0;
if ( ie.eoo() || se.eoo() )
return direction;
}
if ( strcmp( ie.fieldName(), se.fieldName() ) != 0 )
return 0;
@ -146,6 +146,11 @@ namespace mongo {
set<string> queryFields;
query.getFieldNames(queryFields);
if ( queryFields.size() == 0 ) {
DEV out() << "getIndexCursor fail " << ns << '\n';
return auto_ptr<Cursor>();
}
// regular query without order by
for (int i = 0; i < d->nIndexes; i++ ) {
BSONObj idxInfo = d->indexes[i].info.obj(); // { name:, ns:, key: }
@ -153,7 +158,12 @@ namespace mongo {
set<string> keyFields;
idxKey.getFieldNames(keyFields);
if ( keyFields == queryFields ) {
bool subset = true;
for( set<string>::iterator j = queryFields.begin(); subset && j != queryFields.end(); ++j )
if ( keyFields.count( *j ) == 0 )
subset = false;
if ( subset ) {
BSONObj q = query.extractFieldsUnDotted(idxKey);
assert(q.objsize() != 0); // guard against a seg fault if details is 0

4
jstests/index7.js
View File

@ -42,12 +42,14 @@ f.drop();
f.ensureIndex( { a: 1, b: 1 } );
index( f.find().sort( { a: 1, b: 1 } ) );
index( f.find().sort( { a: -1, b: -1 } ) );
index( f.find().sort( { a: 1 } ) );
index( f.find().sort( { a: 1 } ).hint( { a: 1, b: 1 } ) );
noIndex( f.find().sort( { a: 1, b: -1 } ) );
noIndex( f.find().sort( { b: 1, a: 1 } ) );
noIndex( f.find() );
noIndex( f.find( { c: 1 } ) );
noIndex( f.find( { a: 1 } ) ); // Once we enhance the query optimizer, this should get an index.
index( f.find( { a: 1 } ) );
index( f.find( { a: 1, b: 1 } ) );
index( f.find( { b: 1, a: 1 } ) );