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//
// Tests that queries in sharded collections will be properly optimized. In particular, queries
// which specify the shard key fully with an equality predicate may omit a SHARDING_FILTER stage.
//
// @tags: [requires_fcv_49]
(function() {
"use strict";
load("jstests/libs/analyze_plan.js");
function assertShardFilter(explain) {
const filterStage = getPlanStage(explain.queryPlanner.winningPlan, "SHARDING_FILTER");
assert.eq(filterStage.stage, "SHARDING_FILTER");
const scanStage = filterStage.inputStage;
assert.contains(scanStage.stage, ["IXSCAN", "FETCH"]);
}
function assertNoShardFilter(explain) {
const filterStage = getPlanStage(explain.queryPlanner.winningPlan, "SHARDING_FILTER");
assert.eq(filterStage, null, explain);
}
function assertCountScan(explain) {
const countStage = getPlanStage(explain.queryPlanner.winningPlan, "COUNT_SCAN");
assert.eq(countStage.stage, "COUNT_SCAN");
}
const st = new ShardingTest({shards: 1});
const coll = st.s0.getCollection("foo.bar");
function createCollection(coll, shardKey) {
coll.drop();
assert.commandWorked(st.s0.adminCommand({shardCollection: coll.getFullName(), key: shardKey}));
assert.commandWorked(coll.insert({_id: true, a: true, b: true, c: true, d: true}));
assert.commandWorked(coll.createIndex({a: 1, b: 1}));
assert.commandWorked(coll.createIndex({b: 1, a: 1}));
}
assert.commandWorked(st.s0.adminCommand({enableSharding: coll.getDB().getName()}));
jsTest.log('Tests with single shard key');
createCollection(coll, {a: 1});
// We're requesting a specific shard key, therefore we should optimize away SHARDING_FILTER
// and use a cheaper COUNT_SCAN.
let explain = assert.commandWorked(coll.explain('executionStats').count({a: true}));
assertCountScan(explain);
// Check this works with a subset of records as well.
explain = assert.commandWorked(coll.explain('executionStats').count({a: true, b: true}));
assertCountScan(explain);
// Test that a find() query which specifies the entire shard key does not need a shard filter.
explain = assert.commandWorked(coll.find({a: true}).explain());
assertNoShardFilter(explain);
explain = assert.commandWorked(coll.find({a: true, b: true}).explain());
assertNoShardFilter(explain);
// We're not checking shard key for equality, therefore need a sharding filter.
explain = assert.commandWorked(coll.explain('executionStats').count({a: {$in: [true, false]}}));
assertShardFilter(explain);
// We're requesting a disjoint key from shardkey, therefore need a sharding filter.
explain = assert.commandWorked(coll.explain('executionStats').count({b: true}));
assertShardFilter(explain);
jsTest.log('Tests with compound shard key');
createCollection(coll, {a: 1, b: 1});
explain = assert.commandWorked(coll.explain('executionStats').count({a: true}));
assertShardFilter(explain);
explain = assert.commandWorked(coll.explain('executionStats').count({a: true, b: true}));
assertCountScan(explain);
explain =
assert.commandWorked(coll.explain('executionStats').count({a: true, b: {$in: [true, false]}}));
assertShardFilter(explain);
explain = assert.commandWorked(coll.find({a: true}).explain());
assertShardFilter(explain);
explain = assert.commandWorked(coll.find({a: true, b: true}).explain());
assertNoShardFilter(explain);
explain = assert.commandWorked(coll.find({a: true, b: {$in: [true, false]}}).explain());
assertShardFilter(explain);
jsTest.log('Tests with hashed shard key');
createCollection(coll, {a: 'hashed'});
explain = assert.commandWorked(coll.explain('executionStats').count({a: true}));
assertCountScan(explain);
explain = assert.commandWorked(coll.explain('executionStats').count({a: true, b: true}));
assertCountScan(explain);
explain = assert.commandWorked(coll.explain('executionStats').count({a: {$in: [true, false]}}));
assertShardFilter(explain);
explain = assert.commandWorked(coll.explain('executionStats').count({b: true}));
assertShardFilter(explain);
explain = assert.commandWorked(coll.find({a: true}).explain());
assertNoShardFilter(explain);
explain = assert.commandWorked(coll.find({a: true, b: true}).explain());
assertNoShardFilter(explain);
explain = assert.commandWorked(coll.find({a: {$in: [true, false]}}).explain());
assertShardFilter(explain);
explain = assert.commandWorked(coll.find({b: true}).explain());
assertShardFilter(explain);
st.stop();
})();
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