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
|
// Failing due to queries on a sharded collection not able to be covered when they aren't on the
// shard key since the document needs to be fetched in order to apply the SHARDING_FILTER stage.
// @tags: [assumes_unsharded_collection]
/**
* Test projections with dotted field paths. Also test that such projections result in covered plans
* when appropriate.
*/
(function() {
"use strict";
load("jstests/libs/analyze_plan.js");
let coll = db["projection_dotted_paths"];
coll.drop();
assert.commandWorked(coll.createIndex({a: 1, "b.c": 1, "b.d": 1, c: 1}));
assert.commandWorked(coll.insert({_id: 1, a: 1, b: {c: 1, d: 1, e: 1}, c: 1, e: 1}));
// Project exactly the set of fields in the index. Verify that the projection is computed
// correctly and that the plan is covered.
let resultDoc = coll.findOne({a: 1}, {_id: 0, a: 1, "b.c": 1, "b.d": 1, c: 1});
assert.eq(resultDoc, {a: 1, b: {c: 1, d: 1}, c: 1});
let explain = coll.find({a: 1}, {_id: 0, a: 1, "b.c": 1, "b.d": 1, c: 1}).explain("queryPlanner");
assert(isIxscan(db, explain.queryPlanner.winningPlan));
assert(isIndexOnly(db, explain.queryPlanner.winningPlan));
// Project a subset of the indexed fields. Verify that the projection is computed correctly and
// that the plan is covered.
resultDoc = coll.findOne({a: 1}, {_id: 0, "b.c": 1, c: 1});
assert.eq(resultDoc, {b: {c: 1}, c: 1});
explain = coll.find({a: 1}, {_id: 0, "b.c": 1, c: 1}).explain("queryPlanner");
assert(isIxscan(db, explain.queryPlanner.winningPlan));
assert(isIndexOnly(db, explain.queryPlanner.winningPlan));
// Project exactly the set of fields in the index but also include _id. Verify that the
// projection is computed correctly and that the plan cannot be covered.
resultDoc = coll.findOne({a: 1}, {_id: 1, a: 1, "b.c": 1, "b.d": 1, c: 1});
assert.eq(resultDoc, {_id: 1, a: 1, b: {c: 1, d: 1}, c: 1});
explain = coll.find({a: 1}, {_id: 0, "b.c": 1, c: 1}).explain("queryPlanner");
explain = coll.find({a: 1}, {_id: 1, a: 1, "b.c": 1, "b.d": 1, c: 1}).explain("queryPlanner");
assert(isIxscan(db, explain.queryPlanner.winningPlan));
assert(!isIndexOnly(db, explain.queryPlanner.winningPlan));
// Project a not-indexed field that exists in the collection. The plan should not be covered.
resultDoc = coll.findOne({a: 1}, {_id: 0, "b.c": 1, "b.e": 1, c: 1});
assert.eq(resultDoc, {b: {c: 1, e: 1}, c: 1});
explain = coll.find({a: 1}, {_id: 0, "b.c": 1, "b.e": 1, c: 1}).explain("queryPlanner");
assert(isIxscan(db, explain.queryPlanner.winningPlan));
assert(!isIndexOnly(db, explain.queryPlanner.winningPlan));
// Project a not-indexed field that does not exist in the collection. The plan should not be
// covered.
resultDoc = coll.findOne({a: 1}, {_id: 0, "b.c": 1, "b.z": 1, c: 1});
assert.eq(resultDoc, {b: {c: 1}, c: 1});
explain = coll.find({a: 1}, {_id: 0, "b.c": 1, "b.z": 1, c: 1}).explain("queryPlanner");
assert(isIxscan(db, explain.queryPlanner.winningPlan));
assert(!isIndexOnly(db, explain.queryPlanner.winningPlan));
// Verify that the correct projection is computed with an idhack query.
resultDoc = coll.findOne({_id: 1}, {_id: 0, "b.c": 1, "b.e": 1, c: 1});
assert.eq(resultDoc, {b: {c: 1, e: 1}, c: 1});
explain = coll.find({_id: 1}, {_id: 0, "b.c": 1, "b.e": 1, c: 1}).explain("queryPlanner");
assert(isIdhack(db, explain.queryPlanner.winningPlan));
// If we make a dotted path multikey, projections using that path cannot be covered. But
// projections which do not include the multikey path can still be covered.
assert.commandWorked(coll.insert({a: 2, b: {c: 1, d: [1, 2, 3]}}));
resultDoc = coll.findOne({a: 2}, {_id: 0, "b.c": 1, "b.d": 1});
assert.eq(resultDoc, {b: {c: 1, d: [1, 2, 3]}});
explain = coll.find({a: 2}, {_id: 0, "b.c": 1, "b.d": 1}).explain("queryPlanner");
assert(isIxscan(db, explain.queryPlanner.winningPlan));
assert(!isIndexOnly(db, explain.queryPlanner.winningPlan));
resultDoc = coll.findOne({a: 2}, {_id: 0, "b.c": 1});
assert.eq(resultDoc, {b: {c: 1}});
explain = coll.find({a: 2}, {_id: 0, "b.c": 1}).explain("queryPlanner");
assert(isIxscan(db, explain.queryPlanner.winningPlan));
// Path-level multikey info allows for generating a covered plan.
assert(isIndexOnly(db, explain.queryPlanner.winningPlan));
// Verify that dotted projections work for multiple levels of nesting.
assert.commandWorked(coll.createIndex({a: 1, "x.y.y": 1, "x.y.z": 1, "x.z": 1}));
assert.commandWorked(coll.insert({a: 3, x: {y: {y: 1, f: 1, z: 1}, f: 1, z: 1}}));
resultDoc = coll.findOne({a: 3}, {_id: 0, "x.y.y": 1, "x.y.z": 1, "x.z": 1});
assert.eq(resultDoc, {x: {y: {y: 1, z: 1}, z: 1}});
explain = coll.find({a: 3}, {_id: 0, "x.y.y": 1, "x.y.z": 1, "x.z": 1}).explain("queryPlanner");
assert(isIxscan(db, explain.queryPlanner.winningPlan));
assert(isIndexOnly(db, explain.queryPlanner.winningPlan));
// If projected nested paths do not exist in the indexed document, then they will get filled in
// with nulls. This is a bug tracked by SERVER-23229.
resultDoc = coll.findOne({a: 1}, {_id: 0, "x.y.y": 1, "x.y.z": 1, "x.z": 1});
assert.eq(resultDoc, {x: {y: {y: null, z: null}, z: null}});
}());
|
