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//
// Tests that indexes containing the shard key can be used without fetching the document for
// particular queries
//
// Include helpers for analyzing explain output.
load("jstests/libs/analyze_plan.js");
var st = new ShardingTest({shards: 1});
var mongos = st.s0;
var admin = mongos.getDB("admin");
var shards = mongos.getCollection("config.shards").find().toArray();
var coll = mongos.getCollection("foo.bar");
//
//
// Tests with _id : 1 shard key
assert(admin.runCommand({enableSharding: coll.getDB() + ""}).ok);
printjson(admin.runCommand({movePrimary: coll.getDB() + "", to: shards[0]._id}));
assert(admin.runCommand({shardCollection: coll + "", key: {_id: 1}}).ok);
st.printShardingStatus();
// Insert some data
assert.writeOK(coll.insert({_id: true, a: true, b: true}));
assert.commandWorked(
st.shard0.adminCommand({setParameter: 1, logComponentVerbosity: {query: {verbosity: 5}}}));
//
// Index without shard key query - not covered
assert.commandWorked(coll.ensureIndex({a: 1}));
assert.eq(1, coll.find({a: true}).explain(true).executionStats.totalDocsExamined);
assert.eq(1, coll.find({a: true}, {_id: 1, a: 1}).explain(true).executionStats.totalDocsExamined);
//
// Index with shard key query - covered when projecting
assert.commandWorked(coll.dropIndexes());
assert.commandWorked(coll.ensureIndex({a: 1, _id: 1}));
assert.eq(1, coll.find({a: true}).explain(true).executionStats.totalDocsExamined);
assert.eq(0, coll.find({a: true}, {_id: 1, a: 1}).explain(true).executionStats.totalDocsExamined);
//
// Compound index with shard key query - covered when projecting
assert.commandWorked(coll.dropIndexes());
assert.commandWorked(coll.ensureIndex({a: 1, b: 1, _id: 1}));
assert.eq(1, coll.find({a: true, b: true}).explain(true).executionStats.totalDocsExamined);
assert.eq(
0,
coll.find({a: true, b: true}, {_id: 1, a: 1}).explain(true).executionStats.totalDocsExamined);
//
//
// Tests with _id : hashed shard key
coll.drop();
assert(admin.runCommand({shardCollection: coll + "", key: {_id: "hashed"}}).ok);
st.printShardingStatus();
// Insert some data
assert.writeOK(coll.insert({_id: true, a: true, b: true}));
//
// Index without shard key query - not covered
assert.commandWorked(coll.ensureIndex({a: 1}));
assert.eq(1, coll.find({a: true}).explain(true).executionStats.totalDocsExamined);
assert.eq(1, coll.find({a: true}, {_id: 0, a: 1}).explain(true).executionStats.totalDocsExamined);
//
// Index with shard key query - can't be covered since hashed index
assert.commandWorked(coll.dropIndex({a: 1}));
assert.eq(1, coll.find({_id: true}).explain(true).executionStats.totalDocsExamined);
assert.eq(1, coll.find({_id: true}, {_id: 0}).explain(true).executionStats.totalDocsExamined);
//
//
// Tests with compound shard key
coll.drop();
assert(admin.runCommand({shardCollection: coll + "", key: {a: 1, b: 1}}).ok);
st.printShardingStatus();
// Insert some data
assert.writeOK(coll.insert({_id: true, a: true, b: true, c: true, d: true}));
//
// Index without shard key query - not covered
assert.commandWorked(coll.ensureIndex({c: 1}));
assert.eq(1, coll.find({c: true}).explain(true).executionStats.totalDocsExamined);
assert.eq(1,
coll.find({c: true}, {_id: 0, a: 1, b: 1, c: 1})
.explain(true)
.executionStats.totalDocsExamined);
//
// Index with shard key query - covered when projecting
assert.commandWorked(coll.dropIndex({c: 1}));
assert.commandWorked(coll.ensureIndex({c: 1, b: 1, a: 1}));
assert.eq(1, coll.find({c: true}).explain(true).executionStats.totalDocsExamined);
assert.eq(0,
coll.find({c: true}, {_id: 0, a: 1, b: 1, c: 1})
.explain(true)
.executionStats.totalDocsExamined);
//
// Compound index with shard key query - covered when projecting
assert.commandWorked(coll.dropIndex({c: 1, b: 1, a: 1}));
assert.commandWorked(coll.ensureIndex({c: 1, d: 1, a: 1, b: 1, _id: 1}));
assert.eq(1, coll.find({c: true, d: true}).explain(true).executionStats.totalDocsExamined);
assert.eq(0,
coll.find({c: true, d: true}, {a: 1, b: 1, c: 1, d: 1})
.explain(true)
.executionStats.totalDocsExamined);
//
//
// Tests with nested shard key
coll.drop();
assert(admin.runCommand({shardCollection: coll + "", key: {'a.b': 1}}).ok);
st.printShardingStatus();
// Insert some data
assert.writeOK(coll.insert({_id: true, a: {b: true}, c: true}));
//
// Index without shard key query - not covered
assert.commandWorked(coll.ensureIndex({c: 1}));
assert.eq(1, coll.find({c: true}).explain(true).executionStats.totalDocsExamined);
assert.eq(
1,
coll.find({c: true}, {_id: 0, 'a.b': 1, c: 1}).explain(true).executionStats.totalDocsExamined);
//
// Index with shard key query - nested query not covered even when projecting
assert.commandWorked(coll.dropIndex({c: 1}));
assert.commandWorked(coll.ensureIndex({c: 1, 'a.b': 1}));
assert.eq(1, coll.find({c: true}).explain(true).executionStats.totalDocsExamined);
assert.eq(
1,
coll.find({c: true}, {_id: 0, 'a.b': 1, c: 1}).explain(true).executionStats.totalDocsExamined);
//
//
// Tests with bad data with no shard key
coll.drop();
assert(admin.runCommand({shardCollection: coll + "", key: {a: 1}}).ok);
st.printShardingStatus();
// Insert some bad data manually
assert.writeOK(st.shard0.getCollection(coll.toString()).insert({_id: "bad data", c: true}));
//
// Index without shard key query - not covered but succeeds
assert.commandWorked(coll.ensureIndex({c: 1}));
var explain = coll.find({c: true}).explain(true).executionStats;
assert.eq(0, explain.nReturned);
assert.eq(1, explain.totalDocsExamined);
assert.eq(1, getChunkSkips(explain.executionStages.shards[0].executionStages));
//
// Index with shard key query - covered and succeeds and returns result
// NOTE: This is weird and only a result of the fact that we don't have a dedicated "does not exist"
// value for indexes
assert.commandWorked(coll.ensureIndex({c: 1, a: 1}));
jsTest.log(tojson(coll.find({c: true}, {_id: 0, a: 1, c: 1}).toArray()));
var explain = coll.find({c: true}, {_id: 0, a: 1, c: 1}).explain(true).executionStats;
assert.eq(1, explain.nReturned);
assert.eq(0, explain.totalDocsExamined);
assert.eq(0, getChunkSkips(explain.executionStages.shards[0].executionStages));
jsTest.log("DONE!");
st.stop();
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