Files
mongo/jstests/aggregation/sources/unionWith/unionWith_explain.js

266 lines
9.8 KiB
JavaScript

/**
* Test that $unionWith's pipeline argument returns the same explain as an equivalent normal
* pipeline.
* @tags: [
* do_not_wrap_aggregations_in_facets,
* ]
*/
(function() {
"use strict";
load("jstests/aggregation/extras/utils.js"); // arrayEq, documentEq
load("jstests/libs/fixture_helpers.js"); // For FixtureHelpers.
load("jstests/libs/analyze_plan.js"); // For getAggPlanStage.
load("jstests/libs/sbe_util.js"); // For checkSBEEnabled.
const groupPushdownEnabled = checkSBEEnabled(db, ["featureFlagSBEGroupPushdown"]);
const testDB = db.getSiblingDB(jsTestName());
const collA = testDB.A;
collA.drop();
const collB = testDB.B;
collB.drop();
const collC = testDB.C;
collC.drop();
const docsPerColl = 5;
for (let i = 0; i < docsPerColl; i++) {
assert.commandWorked(collA.insert({a: i, val: i, groupKey: i}));
assert.commandWorked(collB.insert({b: i, val: i * 2, groupKey: i}));
assert.commandWorked(collC.insert({c: i, val: 10 - i, groupKey: i}));
}
const executionStatsIngoredFields = [
"executionTimeMillis",
"executionTimeMillisEstimate",
"saveState",
"restoreState",
];
const stagesIgnoredFields = [
"slots",
];
const mongosIgnoredFields = [
"works",
"needTime",
"queryHash",
"planCacheKey",
].concat(executionStatsIngoredFields, stagesIgnoredFields);
const queryPlannerIgnoredFields = [
"optimizedPipeline",
].concat(stagesIgnoredFields);
function getUnionWithStage(explain) {
if (explain.splitPipeline != null) {
// If there is only one shard, the whole pipeline will run on that shard.
const subAggPipe = explain.splitPipeline === null ? explain.shards["shard-rs0"].stages
: explain.splitPipeline.mergerPart;
for (let i = 0; i < subAggPipe.length; i++) {
const stage = subAggPipe[i];
if (stage.hasOwnProperty("$unionWith")) {
return stage;
}
}
} else {
return getAggPlanStage(explain, "$unionWith");
}
}
function buildErrorString(unionExplain, realExplain, field) {
return "Explains did not match in field " + field + ". Union:\n" + tojson(unionExplain) +
"\nRegular:\n" + tojson(realExplain);
}
function anyEqWithIgnoredFields(union, regular, ignoredFields) {
return anyEq(union, regular, false /* verbose */, null /* valueComparator */, ignoredFields);
}
function documentEqWithIgnoredFields(union, regular, ignoredFields) {
return documentEq(
union, regular, false /* verbose */, null /* valueComparator */, ignoredFields);
}
function arrayEqWithIgnoredFields(union, regular, ignoredFields) {
return arrayEq(union, regular, false /* verbose */, null /* valueComparator */, ignoredFields);
}
function assertExplainEq(union, regular) {
if (FixtureHelpers.isMongos(testDB)) {
assert(
anyEqWithIgnoredFields(union.splitPipeline, regular.splitPipeline, mongosIgnoredFields),
buildErrorString(union, regular, "splitPipeline"));
assert.eq(
union.mergeType, regular.mergeType, buildErrorString(union, regular, "mergeType"));
assert(documentEqWithIgnoredFields(union.shards, regular.shards, mongosIgnoredFields),
buildErrorString(union, regular, "shards"));
} else if ("executionStats" in regular) {
const unionStats = union[0].$cursor.executionStats;
const regularStats = regular.executionStats;
assert(documentEqWithIgnoredFields(unionStats.executionStages,
regularStats.executionStages,
executionStatsIngoredFields),
buildErrorString(unionStats, regularStats, "executionStages"));
} else if ("stages" in regular) {
assert(arrayEqWithIgnoredFields(union, regular.stages, stagesIgnoredFields),
buildErrorString(union, regular, "stages"));
} else if ("queryPlanner" in regular) {
assert.eq(union.length, 1, "Expected single union stage");
const unionCursor = union[0].$cursor;
assert(documentEqWithIgnoredFields(
regular.queryPlanner, unionCursor.queryPlanner, queryPlannerIgnoredFields),
buildErrorString(unionCursor, regular, "queryPlanner"));
} else {
assert(false,
"Don't know how to compare following explains.\n" +
"regular: " + tojson(regularExplain) + "\n" +
"union: " + tojson(unionSubExplain) + "\n");
}
}
function assertExplainMatch(unionExplain, regularExplain) {
const unionStage = getUnionWithStage(unionExplain);
assert(unionStage);
const unionSubExplain = unionStage.$unionWith.pipeline;
assertExplainEq(unionSubExplain, regularExplain);
}
function testPipeline(pipeline) {
let unionResult = collA.aggregate([{$unionWith: {coll: collB.getName(), pipeline: pipeline}}],
{explain: true});
let queryResult = collB.aggregate(pipeline, {explain: true});
assertExplainMatch(unionResult, queryResult);
}
testPipeline([{$addFields: {bump: true}}]);
testPipeline([{$group: {_id: "$groupKey", sum: {$sum: "$val"}}}]);
testPipeline([{$group: {_id: "$groupKey", sum: {$sum: "$val"}}}, {$addFields: {bump: true}}]);
testPipeline([{$unionWith: {coll: collC.getName()}}]);
testPipeline([{$unionWith: {coll: collC.getName(), pipeline: [{$addFields: {bump: true}}]}}]);
testPipeline([
{$project: {firstProj: false}},
{$group: {_id: "$groupKey", sum: {$sum: "$val"}}},
{$match: {_id: 2}}
]);
testPipeline([{$limit: 3}, {$sort: {_id: 1}}, {$addFields: {bump: true}}]);
testPipeline([{
$addFields: {
value: {
$function: {
body: function(base, pow) {
return Math.pow(base, pow);
},
args: [2, 3],
lang: "js"
}
}
}
}]);
// Ensure that both agg with the explain argument and the explain command work.
assert.commandWorked(testDB.runCommand({
aggregate: collA.getName(),
pipeline: [{$unionWith: collB.getName()}],
cursor: {},
explain: true
}));
assert.commandWorked(testDB.runCommand({
explain: {
aggregate: collA.getName(),
pipeline: [{$unionWith: collB.getName()}],
cursor: {},
}
}));
// Ensure that $unionWith can still execute explain if followed by a stage that calls dispose().
let result = assert.commandWorked(testDB.runCommand({
explain: {
aggregate: collA.getName(),
pipeline: [{$unionWith: collB.getName()}, {$limit: 1}],
cursor: {},
}
}));
// Test that execution stats inner cursor is populated.
result = collA.explain("executionStats").aggregate([{"$unionWith": collB.getName()}]);
assert.commandWorked(result);
let expectedResult = collB.explain("executionStats").aggregate([]);
assert.commandWorked(expectedResult);
let unionStage = getUnionWithStage(result);
assert(unionStage, result);
if (FixtureHelpers.isMongos(testDB)) {
assert(documentEqWithIgnoredFields(
expectedResult.shards, unionStage.$unionWith.pipeline.shards, mongosIgnoredFields),
buildErrorString(unionStage, expectedResult));
// TODO SERVER-50597 Fix unionWith nReturned stat in sharded cluster
// assert.eq(unionStage.nReturned, docsPerColl, unionStage);
} else {
assert.eq(unionStage.nReturned, docsPerColl * 2, unionStage);
assert.eq(unionStage.$unionWith.pipeline[0].$cursor.executionStats.nReturned,
docsPerColl,
unionStage);
}
// Test explain with executionStats when the $unionWith stage doesn't need to read from it's
// sub-pipeline.
result = collA.explain("executionStats").aggregate([{"$unionWith": collB.getName()}, {$limit: 1}]);
assert.commandWorked(result);
unionStage = getUnionWithStage(result);
assert(unionStage, result);
if (!FixtureHelpers.isSharded(collB)) {
assert.eq(unionStage.nReturned, 1, unionStage);
assert.eq(unionStage.$unionWith, {coll: "B", pipeline: []}, unionStage);
}
// Test explain with executionStats when the $unionWith stage partially reads from it's
// sub-pipeline.
result = collA.explain("executionStats")
.aggregate([{"$unionWith": collB.getName()}, {$limit: docsPerColl + 1}]);
assert.commandWorked(result);
unionStage = getUnionWithStage(result);
assert(unionStage, result);
if (!FixtureHelpers.isSharded(collB)) {
assert.eq(unionStage.nReturned, docsPerColl + 1, unionStage);
// TODO SERVER-50597 Fix the executionStats of $unionWith sub-pipeline, the actual result should
// be 1 instead of docsPerColl.
assert.eq(unionStage.$unionWith.pipeline[0].$cursor.executionStats.nReturned,
docsPerColl,
unionStage);
}
// Test an index scan.
const indexedColl = testDB.indexed;
assert.commandWorked(indexedColl.createIndex({val: 1}));
indexedColl.insert([{val: 0}, {val: 1}, {val: 2}, {val: 3}]);
result = collA.explain("executionStats").aggregate([
{$unionWith: {coll: indexedColl.getName(), pipeline: [{$match: {val: {$gt: 2}}}]}}
]);
expectedResult = indexedColl.explain("executionStats").aggregate([{$match: {val: {$gt: 2}}}]);
assertExplainMatch(result, expectedResult);
// Test a nested $unionWith which itself should perform an index scan.
testPipeline([{$unionWith: {coll: indexedColl.getName(), pipeline: [{$match: {val: {$gt: 0}}}]}}]);
// Similar test as above, except the $match is pushed down to the inner pipeline as part of a
// rewrite optimization.
const res = db.adminCommand({getParameter: 1, "failpoint.disablePipelineOptimization": 1});
assert.commandWorked(res);
if (!res["failpoint.disablePipelineOptimization"].mode) {
result = collA.explain("executionStats")
.aggregate([{$unionWith: indexedColl.getName()}, {$match: {val: {$gt: 2}}}]);
expectedResult = indexedColl.explain("executionStats").aggregate([{$match: {val: {$gt: 2}}}]);
assertExplainMatch(result, expectedResult);
}
})();