1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
|
/**
* Copyright (C) 2018-present MongoDB, Inc.
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the Server Side Public License, version 1,
* as published by MongoDB, Inc.
*
* 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
* Server Side Public License for more details.
*
* You should have received a copy of the Server Side Public License
* along with this program. If not, see
* <http://www.mongodb.com/licensing/server-side-public-license>.
*
* 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 Server Side 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.
*/
/**
* This file tests db/query/plan_ranker.cpp and db/query/multi_plan_runner.cpp.
*/
#include "mongo/platform/basic.h"
#include <iostream>
#include "mongo/client/dbclient_cursor.h"
#include "mongo/db/catalog/collection.h"
#include "mongo/db/catalog/database.h"
#include "mongo/db/client.h"
#include "mongo/db/db_raii.h"
#include "mongo/db/dbdirectclient.h"
#include "mongo/db/exec/multi_plan.h"
#include "mongo/db/index/index_descriptor.h"
#include "mongo/db/json.h"
#include "mongo/db/namespace_string.h"
#include "mongo/db/query/get_executor.h"
#include "mongo/db/query/query_knobs.h"
#include "mongo/db/query/query_planner.h"
#include "mongo/db/query/query_planner_test_lib.h"
#include "mongo/db/query/stage_builder.h"
#include "mongo/dbtests/dbtests.h"
#include "mongo/stdx/memory.h"
namespace mongo {
// How we access the external setParameter testing bool.
extern AtomicWord<bool> internalQueryForceIntersectionPlans;
extern AtomicWord<bool> internalQueryPlannerEnableHashIntersection;
} // namespace mongo
namespace PlanRankingTests {
using std::unique_ptr;
using std::vector;
static const NamespaceString nss("unittests.PlanRankingTests");
class PlanRankingTestBase {
public:
PlanRankingTestBase()
: _internalQueryForceIntersectionPlans(internalQueryForceIntersectionPlans.load()),
_enableHashIntersection(internalQueryPlannerEnableHashIntersection.load()),
_client(&_opCtx) {
// Run all tests with hash-based intersection enabled.
internalQueryPlannerEnableHashIntersection.store(true);
// Ensure N is significantly larger then internalQueryPlanEvaluationWorks.
ASSERT_GTE(N, internalQueryPlanEvaluationWorks.load() + 1000);
dbtests::WriteContextForTests ctx(&_opCtx, nss.ns());
_client.dropCollection(nss.ns());
}
virtual ~PlanRankingTestBase() {
// Restore external setParameter testing bools.
internalQueryForceIntersectionPlans.store(_internalQueryForceIntersectionPlans);
internalQueryPlannerEnableHashIntersection.store(_enableHashIntersection);
}
void insert(const BSONObj& obj) {
dbtests::WriteContextForTests ctx(&_opCtx, nss.ns());
_client.insert(nss.ns(), obj);
}
void addIndex(const BSONObj& obj) {
ASSERT_OK(dbtests::createIndex(&_opCtx, nss.ns(), obj));
}
/**
* Use the MultiPlanRunner to pick the best plan for the query 'cq'. Goes through
* normal planning to generate solutions and feeds them to the MPR.
*
* Does NOT take ownership of 'cq'. Caller DOES NOT own the returned QuerySolution*.
*/
QuerySolution* pickBestPlan(CanonicalQuery* cq) {
AutoGetCollectionForReadCommand ctx(&_opCtx, nss);
Collection* collection = ctx.getCollection();
QueryPlannerParams plannerParams;
fillOutPlannerParams(&_opCtx, collection, cq, &plannerParams);
// Plan.
auto statusWithSolutions = QueryPlanner::plan(*cq, plannerParams);
ASSERT_OK(statusWithSolutions.getStatus());
auto solutions = std::move(statusWithSolutions.getValue());
ASSERT_GREATER_THAN_OR_EQUALS(solutions.size(), 1U);
// Fill out the MPR.
_mps.reset(new MultiPlanStage(&_opCtx, collection, cq));
unique_ptr<WorkingSet> ws(new WorkingSet());
// Put each solution from the planner into the MPR.
for (size_t i = 0; i < solutions.size(); ++i) {
PlanStage* root;
ASSERT(StageBuilder::build(&_opCtx, collection, *cq, *solutions[i], ws.get(), &root));
// Takes ownership of 'root'.
_mps->addPlan(std::move(solutions[i]), root, ws.get());
}
// This is what sets a backup plan, should we test for it.
PlanYieldPolicy yieldPolicy(PlanExecutor::NO_YIELD,
_opCtx.getServiceContext()->getFastClockSource());
_mps->pickBestPlan(&yieldPolicy).transitional_ignore();
ASSERT(_mps->bestPlanChosen());
size_t bestPlanIdx = _mps->bestPlanIdx();
ASSERT_LESS_THAN(bestPlanIdx, solutions.size());
// And return a pointer to the best solution.
return _mps->bestSolution();
}
/**
* Was a backup plan picked during the ranking process?
*/
bool hasBackupPlan() const {
ASSERT(NULL != _mps.get());
return _mps->hasBackupPlan();
}
OperationContext* opCtx() {
return &_opCtx;
}
protected:
// A large number, which must be larger than the number of times
// candidate plans are worked by the multi plan runner. Used for
// determining the number of documents in the tests below.
const int N = 12000;
const ServiceContext::UniqueOperationContext _txnPtr = cc().makeOperationContext();
OperationContext& _opCtx = *_txnPtr;
private:
// Holds the value of global "internalQueryForceIntersectionPlans" setParameter flag.
// Restored at end of test invocation regardless of test result.
bool _internalQueryForceIntersectionPlans;
// Holds the value of the global set parameter so it can be restored at the end
// of the test.
bool _enableHashIntersection;
unique_ptr<MultiPlanStage> _mps;
DBDirectClient _client;
};
/**
* Test that the "prefer ixisect" parameter works.
*/
class PlanRankingIntersectOverride : public PlanRankingTestBase {
public:
void run() {
// 'a' is very selective, 'b' is not.
for (int i = 0; i < N; ++i) {
insert(BSON("a" << i << "b" << 1));
}
// Add indices on 'a' and 'b'.
addIndex(BSON("a" << 1));
addIndex(BSON("b" << 1));
unique_ptr<CanonicalQuery> cq;
// Run the query {a:4, b:1}.
{
auto qr = stdx::make_unique<QueryRequest>(nss);
qr->setFilter(BSON("a" << 100 << "b" << 1));
auto statusWithCQ = CanonicalQuery::canonicalize(opCtx(), std::move(qr));
verify(statusWithCQ.isOK());
cq = std::move(statusWithCQ.getValue());
ASSERT(cq.get());
}
// {a:100} is super selective so choose that.
QuerySolution* soln = pickBestPlan(cq.get());
ASSERT(QueryPlannerTestLib::solutionMatches(
"{fetch: {filter: {b:1}, node: {ixscan: {pattern: {a: 1}}}}}", soln->root.get()));
// Turn on the "force intersect" option.
// This will be reverted by PlanRankingTestBase's destructor when the test completes.
internalQueryForceIntersectionPlans.store(true);
// And run the same query again.
{
auto qr = stdx::make_unique<QueryRequest>(nss);
qr->setFilter(BSON("a" << 100 << "b" << 1));
auto statusWithCQ = CanonicalQuery::canonicalize(opCtx(), std::move(qr));
verify(statusWithCQ.isOK());
cq = std::move(statusWithCQ.getValue());
}
// With the "ranking picks ixisect always" option we pick an intersection plan that uses
// both the {a:1} and {b:1} indices even though it performs poorly.
soln = pickBestPlan(cq.get());
ASSERT(
QueryPlannerTestLib::solutionMatches("{fetch: {node: {andSorted: {nodes: ["
"{ixscan: {filter: null, pattern: {a:1}}},"
"{ixscan: {filter: null, pattern: {b:1}}}]}}}}",
soln->root.get()));
}
};
/**
* Test that a hashed AND solution plan is picked along with a non-blocking backup solution.
*/
class PlanRankingIntersectWithBackup : public PlanRankingTestBase {
public:
void run() {
// 'a' is very selective, 'b' is not.
for (int i = 0; i < N; ++i) {
insert(BSON("a" << i << "b" << 1));
}
// Add indices on 'a' and 'b'.
addIndex(BSON("a" << 1));
addIndex(BSON("b" << 1));
// Run the query {a:1, b:{$gt:1}.
auto qr = stdx::make_unique<QueryRequest>(nss);
qr->setFilter(BSON("a" << 1 << "b" << BSON("$gt" << 1)));
auto statusWithCQ = CanonicalQuery::canonicalize(opCtx(), std::move(qr));
verify(statusWithCQ.isOK());
unique_ptr<CanonicalQuery> cq = std::move(statusWithCQ.getValue());
ASSERT(NULL != cq.get());
// Turn on the "force intersect" option.
// This will be reverted by PlanRankingTestBase's destructor when the test completes.
internalQueryForceIntersectionPlans.store(true);
QuerySolution* soln = pickBestPlan(cq.get());
ASSERT(
QueryPlannerTestLib::solutionMatches("{fetch: {node: {andHash: {nodes: ["
"{ixscan: {filter: null, pattern: {a:1}}},"
"{ixscan: {filter: null, pattern: {b:1}}}]}}}}",
soln->root.get()));
// Confirm that a backup plan is available.
ASSERT(hasBackupPlan());
}
};
/**
* Two plans hit EOF at the same time, but one is covered. Make sure that we prefer the covered
* plan.
*/
class PlanRankingPreferCovered : public PlanRankingTestBase {
public:
void run() {
// Insert data {a:i, b:i}. Index {a:1} and {a:1, b:1}, query on 'a', projection on 'a'
// and 'b'. Should prefer the second index as we can pull the 'b' data out.
for (int i = 0; i < N; ++i) {
insert(BSON("a" << i << "b" << i));
}
addIndex(BSON("a" << 1));
addIndex(BSON("a" << 1 << "b" << 1));
// Query for a==27 with projection that wants 'a' and 'b'.
auto qr = stdx::make_unique<QueryRequest>(nss);
qr->setFilter(BSON("a" << 27));
qr->setProj(BSON("_id" << 0 << "a" << 1 << "b" << 1));
auto statusWithCQ = CanonicalQuery::canonicalize(opCtx(), std::move(qr));
ASSERT_OK(statusWithCQ.getStatus());
unique_ptr<CanonicalQuery> cq = std::move(statusWithCQ.getValue());
ASSERT(NULL != cq.get());
QuerySolution* soln = pickBestPlan(cq.get());
// Prefer the fully covered plan.
ASSERT(QueryPlannerTestLib::solutionMatches(
"{proj: {spec: {_id:0, a:1, b:1}, node: {ixscan: {pattern: {a: 1, b:1}}}}}",
soln->root.get()));
}
};
/**
* No plan produces any results or hits EOF. In this case we should never choose an index
* intersection solution.
*/
class PlanRankingAvoidIntersectIfNoResults : public PlanRankingTestBase {
public:
void run() {
// We insert lots of copies of {a:1, b:1, c: 20}. We have the indices {a:1} and {b:1},
// and the query is {a:1, b:1, c: 999}. No data that matches the query but we won't
// know that during plan ranking. We don't want to choose an intersection plan here.
for (int i = 0; i < N; ++i) {
insert(BSON("a" << 1 << "b" << 1 << "c" << 20));
}
addIndex(BSON("a" << 1));
addIndex(BSON("b" << 1));
// There is no data that matches this query but we don't know that until EOF.
auto qr = stdx::make_unique<QueryRequest>(nss);
qr->setFilter(BSON("a" << 1 << "b" << 1 << "c" << 99));
auto statusWithCQ = CanonicalQuery::canonicalize(opCtx(), std::move(qr));
ASSERT_OK(statusWithCQ.getStatus());
unique_ptr<CanonicalQuery> cq = std::move(statusWithCQ.getValue());
ASSERT(NULL != cq.get());
QuerySolution* soln = pickBestPlan(cq.get());
// Anti-prefer the intersection plan.
bool bestIsScanOverA = QueryPlannerTestLib::solutionMatches(
"{fetch: {node: {ixscan: {pattern: {a: 1}}}}}", soln->root.get());
bool bestIsScanOverB = QueryPlannerTestLib::solutionMatches(
"{fetch: {node: {ixscan: {pattern: {b: 1}}}}}", soln->root.get());
ASSERT(bestIsScanOverA || bestIsScanOverB);
}
};
/**
* No plan produces any results or hits EOF. In this case we should prefer covered solutions to
* non-covered solutions.
*/
class PlanRankingPreferCoveredEvenIfNoResults : public PlanRankingTestBase {
public:
void run() {
// We insert lots of copies of {a:1, b:1}. We have the indices {a:1} and {a:1, b:1},
// the query is for a doc that doesn't exist, but there is a projection over 'a' and
// 'b'. We should prefer the index that provides a covered query.
for (int i = 0; i < N; ++i) {
insert(BSON("a" << 1 << "b" << 1));
}
addIndex(BSON("a" << 1));
addIndex(BSON("a" << 1 << "b" << 1));
// There is no data that matches this query ({a:2}). Both scans will hit EOF before
// returning any data.
auto qr = stdx::make_unique<QueryRequest>(nss);
qr->setFilter(BSON("a" << 2));
qr->setProj(BSON("_id" << 0 << "a" << 1 << "b" << 1));
auto statusWithCQ = CanonicalQuery::canonicalize(opCtx(), std::move(qr));
ASSERT_OK(statusWithCQ.getStatus());
unique_ptr<CanonicalQuery> cq = std::move(statusWithCQ.getValue());
ASSERT(NULL != cq.get());
QuerySolution* soln = pickBestPlan(cq.get());
// Prefer the fully covered plan.
ASSERT(QueryPlannerTestLib::solutionMatches(
"{proj: {spec: {_id:0, a:1, b:1}, node: {ixscan: {pattern: {a: 1, b:1}}}}}",
soln->root.get()));
}
};
/**
* We have an index on "a" which is somewhat selective and an index on "b" which is highly
* selective (will cause an immediate EOF). Make sure that a query with predicates on both "a"
* and "b" will use the index on "b".
*/
class PlanRankingPreferImmediateEOF : public PlanRankingTestBase {
public:
void run() {
// 'a' is very selective, 'b' is not.
for (int i = 0; i < N; ++i) {
insert(BSON("a" << i << "b" << 1));
}
// Add indices on 'a' and 'b'.
addIndex(BSON("a" << 1));
addIndex(BSON("b" << 1));
// Run the query {a:N+1, b:1}. (No such document.)
auto qr = stdx::make_unique<QueryRequest>(nss);
qr->setFilter(BSON("a" << N + 1 << "b" << 1));
auto statusWithCQ = CanonicalQuery::canonicalize(opCtx(), std::move(qr));
verify(statusWithCQ.isOK());
unique_ptr<CanonicalQuery> cq = std::move(statusWithCQ.getValue());
ASSERT(NULL != cq.get());
// {a: 100} is super selective so choose that.
QuerySolution* soln = pickBestPlan(cq.get());
ASSERT(QueryPlannerTestLib::solutionMatches(
"{fetch: {filter: {b:1}, node: {ixscan: {pattern: {a: 1}}}}}", soln->root.get()));
}
};
/**
* Same as PlanRankingPreferImmediateEOF, but substitute a range predicate on "a" for the
* equality predicate on "a". The presence of the range predicate has an impact on the
* intersection plan that is raced against the single-index plans: since "a" no longer generates
* point interval bounds, the results of the index scan aren't guaranteed to be returned in
* RecordId order, and so the intersection plan uses the AND_HASHED stage instead of the
* AND_SORTED stage. It is still the case that the query should pick the plan that uses index
* "b", instead of the plan that uses index "a" or the (hashed) intersection plan.
*/
class PlanRankingPreferImmediateEOFAgainstHashed : public PlanRankingTestBase {
public:
void run() {
// 'a' is very selective, 'b' is not.
for (int i = 0; i < N; ++i) {
insert(BSON("a" << i << "b" << 1));
}
// Add indices on 'a' and 'b'.
addIndex(BSON("a" << 1));
addIndex(BSON("b" << 1));
// Run the query {a:N+1, b:1}. (No such document.)
auto qr = stdx::make_unique<QueryRequest>(nss);
qr->setFilter(BSON("a" << BSON("$gte" << N + 1) << "b" << 1));
auto statusWithCQ = CanonicalQuery::canonicalize(opCtx(), std::move(qr));
verify(statusWithCQ.isOK());
unique_ptr<CanonicalQuery> cq = std::move(statusWithCQ.getValue());
ASSERT(NULL != cq.get());
// {a: 100} is super selective so choose that.
QuerySolution* soln = pickBestPlan(cq.get());
ASSERT(QueryPlannerTestLib::solutionMatches(
"{fetch: {filter: {b:1}, node: {ixscan: {pattern: {a: 1}}}}}", soln->root.get()));
}
};
/**
* We have an index on _id and a query over _id with a sort. Ensure that we don't pick a
* collscan as the best plan even though the _id-scanning solution doesn't produce any results.
*/
class PlanRankingNoCollscan : public PlanRankingTestBase {
public:
void run() {
for (int i = 0; i < N; ++i) {
insert(BSON("_id" << i));
}
addIndex(BSON("_id" << 1));
// Run a query with a sort. The blocking sort won't produce any data during the
// evaluation period.
auto qr = stdx::make_unique<QueryRequest>(nss);
qr->setFilter(BSON("_id" << BSON("$gte" << 20 << "$lte" << 200)));
qr->setSort(BSON("c" << 1));
auto statusWithCQ = CanonicalQuery::canonicalize(opCtx(), std::move(qr));
ASSERT_OK(statusWithCQ.getStatus());
unique_ptr<CanonicalQuery> cq = std::move(statusWithCQ.getValue());
QuerySolution* soln = pickBestPlan(cq.get());
// The best must not be a collscan.
ASSERT(QueryPlannerTestLib::solutionMatches(
"{sort: {pattern: {c: 1}, limit: 0, node: {sortKeyGen: {node:"
"{fetch: {filter: null, node: "
"{ixscan: {filter: null, pattern: {_id: 1}}}}}}}}}",
soln->root.get()));
}
};
/**
* No indices are available, output a collscan.
*/
class PlanRankingCollscan : public PlanRankingTestBase {
public:
void run() {
// Insert data for which we have no index.
for (int i = 0; i < N; ++i) {
insert(BSON("foo" << i));
}
// Look for A Space Odyssey.
auto qr = stdx::make_unique<QueryRequest>(nss);
qr->setFilter(BSON("foo" << 2001));
auto statusWithCQ = CanonicalQuery::canonicalize(opCtx(), std::move(qr));
verify(statusWithCQ.isOK());
unique_ptr<CanonicalQuery> cq = std::move(statusWithCQ.getValue());
ASSERT(NULL != cq.get());
QuerySolution* soln = pickBestPlan(cq.get());
// The best must be a collscan.
ASSERT(QueryPlannerTestLib::solutionMatches("{cscan: {dir: 1, filter: {foo: 2001}}}",
soln->root.get()));
}
};
/**
* When no other information is available, prefer solutions without
* a blocking sort stage.
*/
class PlanRankingAvoidBlockingSort : public PlanRankingTestBase {
public:
void run() {
for (int i = 0; i < N; ++i) {
insert(BSON("a" << 1 << "d" << i));
}
// The index {d: 1, e: 1} provides the desired sort order,
// while index {a: 1, b: 1} can be used to answer the
// query predicate, but does not provide the sort.
addIndex(BSON("a" << 1 << "b" << 1));
addIndex(BSON("d" << 1 << "e" << 1));
// Query: find({a: 1}).sort({d: 1})
auto qr = stdx::make_unique<QueryRequest>(nss);
qr->setFilter(BSON("a" << 1));
qr->setSort(BSON("d" << 1));
auto statusWithCQ = CanonicalQuery::canonicalize(opCtx(), std::move(qr));
ASSERT_OK(statusWithCQ.getStatus());
unique_ptr<CanonicalQuery> cq = std::move(statusWithCQ.getValue());
ASSERT(NULL != cq.get());
// No results will be returned during the trial period,
// so we expect to choose {d: 1, e: 1}, as it allows us
// to avoid the sort stage.
QuerySolution* soln = pickBestPlan(cq.get());
ASSERT(
QueryPlannerTestLib::solutionMatches("{fetch: {filter: {a:1}, node: "
"{ixscan: {filter: null, pattern: {d:1,e:1}}}}}",
soln->root.get()));
}
};
/**
* Make sure we run candidate plans for long enough when none of the
* plans are producing results.
*/
class PlanRankingWorkPlansLongEnough : public PlanRankingTestBase {
public:
void run() {
for (int i = 0; i < N; ++i) {
insert(BSON("a" << 1));
insert(BSON("a" << 1 << "b" << 1 << "c" << i));
}
// Indices on 'a' and 'b'.
addIndex(BSON("a" << 1));
addIndex(BSON("b" << 1));
// Solutions using either 'a' or 'b' will take a long time to start producing
// results. However, an index scan on 'b' will start producing results sooner
// than an index scan on 'a'.
auto qr = stdx::make_unique<QueryRequest>(nss);
qr->setFilter(fromjson("{a: 1, b: 1, c: {$gte: 5000}}"));
auto statusWithCQ = CanonicalQuery::canonicalize(opCtx(), std::move(qr));
ASSERT_OK(statusWithCQ.getStatus());
unique_ptr<CanonicalQuery> cq = std::move(statusWithCQ.getValue());
ASSERT(NULL != cq.get());
// Use index on 'b'.
QuerySolution* soln = pickBestPlan(cq.get());
ASSERT(QueryPlannerTestLib::solutionMatches("{fetch: {node: {ixscan: {pattern: {b: 1}}}}}",
soln->root.get()));
}
};
/**
* Suppose we have two plans which are roughly equivalent, other than that
* one uses an index which involves doing a lot more skipping of index keys.
* Prefer the plan which does not have to do this index key skipping.
*/
class PlanRankingAccountForKeySkips : public PlanRankingTestBase {
public:
void run() {
for (int i = 0; i < 100; ++i) {
insert(BSON("a" << i << "b" << i << "c" << i));
}
// These indices look equivalent to the ranker for the query below unless we account
// for key skipping. We should pick index {a: 1} if we account for key skipping
// properly.
addIndex(BSON("b" << 1 << "c" << 1));
addIndex(BSON("a" << 1));
auto qr = stdx::make_unique<QueryRequest>(nss);
qr->setFilter(fromjson("{a: 9, b: {$ne: 10}, c: 9}"));
auto statusWithCQ = CanonicalQuery::canonicalize(opCtx(), std::move(qr));
ASSERT_OK(statusWithCQ.getStatus());
unique_ptr<CanonicalQuery> cq = std::move(statusWithCQ.getValue());
ASSERT(NULL != cq.get());
// Expect to use index {a: 1, b: 1}.
QuerySolution* soln = pickBestPlan(cq.get());
ASSERT(QueryPlannerTestLib::solutionMatches("{fetch: {node: {ixscan: {pattern: {a: 1}}}}}",
soln->root.get()));
}
};
class All : public Suite {
public:
All() : Suite("query_plan_ranking") {}
void setupTests() {
add<PlanRankingIntersectOverride>();
add<PlanRankingIntersectWithBackup>();
add<PlanRankingPreferCovered>();
add<PlanRankingAvoidIntersectIfNoResults>();
add<PlanRankingPreferCoveredEvenIfNoResults>();
add<PlanRankingPreferImmediateEOF>();
add<PlanRankingPreferImmediateEOFAgainstHashed>();
add<PlanRankingNoCollscan>();
add<PlanRankingCollscan>();
add<PlanRankingAvoidBlockingSort>();
add<PlanRankingWorkPlansLongEnough>();
add<PlanRankingAccountForKeySkips>();
}
};
SuiteInstance<All> planRankingAll;
} // namespace PlanRankingTest
|