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/**
* Test that redundant sorts are removed/swapped.
*
* @tags: [
* assumes_unsharded_collection,
* do_not_wrap_aggregations_in_facets,
* requires_pipeline_optimization,
* requires_fcv_50,
* ]
*/
(function() {
"use strict";
load('jstests/libs/analyze_plan.js');
// Find how many stages of the plan are 'stageName'.
function numberOfStages(explain, stageName) {
return getAggPlanStages(explain, stageName).length;
}
const coll = db[jsTestName()];
coll.drop();
assert.commandWorked(coll.insert([
{a: {b: 3, c: 3}, b: 2, c: 1},
{a: {b: 3, c: 3}, b: 4, c: 1},
{a: {b: 1, c: 1}, b: 4, c: 1},
{a: {b: 2, c: 2}, b: 1, c: 1},
{a: {b: 1, c: 1}, b: 4, c: 1},
{a: {b: 3, c: 3}, b: 2, c: 1},
{a: {b: 2, c: 2}, b: 1, c: 1},
{a: {b: 2, c: 2}, b: 1, c: 1},
{a: {b: 2, c: 2}, b: 3, c: 1},
{a: {b: 1, c: 1}, b: 4, c: 1},
]));
const explain1 = coll.explain().aggregate([
{$_internalInhibitOptimization: {}},
{
$setWindowFields: {
sortBy: {a: 1, b: 1},
output: {sum: {$sum: "$c", window: {documents: ["unbounded", "current"]}}}
}
},
{$sort: {a: 1}}
]);
// Redundant $sort should be removed.
assert.eq(1, numberOfStages(explain1, '$sort'), explain1);
// We keep the more specific sort.
assert.docEq(getAggPlanStages(explain1, '$sort'), [{$sort: {sortKey: {a: 1, b: 1}}}], explain1);
const explain2 = coll.explain().aggregate([
{$_internalInhibitOptimization: {}},
{
$setWindowFields: {
sortBy: {a: 1, b: 1},
output: {sum: {$sum: "$c", window: {documents: ["unbounded", "current"]}}}
}
},
{$sort: {a: -1}}
]);
// $sort is not redundant, should not be removed.
assert.eq(2, numberOfStages(explain2, '$sort'), explain2);
const explain3 = coll.explain().aggregate([
{$_internalInhibitOptimization: {}},
{
$setWindowFields: {
sortBy: {a: 1},
output: {sum: {$sum: "$c", window: {documents: ["unbounded", "current"]}}}
}
},
{$sort: {a: 1, b: -1}}
]);
// $sort should be swapped with $_internalSetWindowFields, and the extra one removed.
assert.eq(1, numberOfStages(explain3, '$sort'), explain3);
// The sort we keep should be the more specific one.
assert.docEq(getAggPlanStages(explain3, '$sort'), [{$sort: {sortKey: {a: 1, b: -1}}}], explain3);
const explain4 = coll.explain().aggregate([
{$_internalInhibitOptimization: {}},
{
$setWindowFields: {
sortBy: {a: 1},
output: {a: {$sum: "$c", window: {documents: ["unbounded", "current"]}}}
}
},
{$sort: {a: 1}}
]);
// Sort field is modified, can't be swapped or removed.
assert.eq(2, numberOfStages(explain4, '$sort'), explain4);
const explain5 = coll.explain().aggregate([
{$_internalInhibitOptimization: {}},
{
$setWindowFields: {
sortBy: {a: 1},
output: {'a.b': {$sum: "$c", window: {documents: ["unbounded", "current"]}}}
}
},
{$sort: {a: 1}}
]);
// Sort field is modified, can't be swapped or removed.
assert.eq(2, numberOfStages(explain5, '$sort'), explain5);
const explain6 = coll.explain().aggregate([
{$_internalInhibitOptimization: {}},
{
$setWindowFields: {
sortBy: {a: 1},
output: {sum: {$sum: "$c", window: {documents: ["unbounded", "current"]}}}
}
},
{$sort: {a: 1}},
{$limit: 5}
]);
// $sort + $limit should not be merged.
assert(aggPlanHasStage(explain6, "$limit"), explain6);
// The $limit should not prevent us from removing the redundant $sort.
assert.eq(1, numberOfStages(explain6, '$sort'), explain6);
const explain7 = coll.explain().aggregate([
{$_internalInhibitOptimization: {}},
{$setWindowFields: {partitionBy: "$a.b", output: {sum: {$sum: "$c"}}}},
{$sort: {'a.b': 1}}
]);
// Sort should be removed if sorting and partitioning on same field.
assert.eq(1, numberOfStages(explain7, '$sort'), explain7);
const explain8 = coll.explain().aggregate([
{$_internalInhibitOptimization: {}},
{
$setWindowFields: {
partitionBy: "$a.c",
sortBy: {'a.b': 1},
output: {sum: {$sum: "$c", window: {documents: ["unbounded", "current"]}}}
}
},
{$sort: {'a.b': 1}}
]);
// Sort should not be removed since primary sort field is "a.c".
assert.eq(2, numberOfStages(explain8, '$sort'), explain8);
const explain9 = coll.explain().aggregate([
{$_internalInhibitOptimization: {}},
{
$setWindowFields: {
partitionBy: "$a.c",
sortBy: {'a.b': 1},
output: {sum: {$sum: "$c", window: {documents: ["unbounded", "current"]}}}
}
},
{$sort: {'a.c': 1}}
]);
// Sort should be removed since primary sort field is "a.c".
assert.eq(1, numberOfStages(explain9, '$sort'), explain9);
// Multiple redundant sorts are dropped.
const explain10 = coll.explain().aggregate([
{$_internalInhibitOptimization: {}},
{
$setWindowFields: {
sortBy: {a: 1, b: 1, c: 1},
output: {sum: {$sum: "$c", window: {documents: ["unbounded", "current"]}}}
}
},
{$sort: {a: 1, b: 1}},
{$sort: {a: 1}},
{$sort: {a: 1, b: 1}},
]);
assert.eq(1, numberOfStages(explain10, '$sort'), explain10);
assert.docEq(
getAggPlanStages(explain10, '$sort'), [{$sort: {sortKey: {a: 1, b: 1, c: 1}}}], explain10);
// Multiple compatible sorts are pushed down.
const explain11 = coll.explain().aggregate([
{$_internalInhibitOptimization: {}},
{
$setWindowFields: {
sortBy: {a: 1},
output: {sum: {$sum: "$c", window: {documents: ["unbounded", "current"]}}}
}
},
{$sort: {a: 1, b: 1, c: 1}},
{$sort: {a: 1, b: 1}},
{$sort: {a: 1, b: 1, c: 1}},
]);
assert.eq(1, numberOfStages(explain11, '$sort'), explain11);
assert.docEq(
getAggPlanStages(explain11, '$sort'), [{$sort: {sortKey: {a: 1, b: 1, c: 1}}}], explain11);
// An incompatible $meta sort should not be dropped or pushed down.
coll.createIndex({'$**': 'text'});
const explain12 = coll.explain().aggregate([
{$match: {$text: {$search: 'hi'}}},
{$_internalInhibitOptimization: {}},
{
$setWindowFields: {
sortBy: {a: 1},
output: {sum: {$sum: "$c", window: {documents: ["unbounded", "current"]}}}
}
},
{$sort: {a: {$meta: "textScore"}}},
]);
assert.eq(2, numberOfStages(explain12, '$sort'), explain12);
// For now, we don't handle $meta at all: it won't be optimized even if it's compatible.
const explain13 = coll.explain().aggregate([
{$match: {$text: {$search: 'hi'}}},
{$_internalInhibitOptimization: {}},
{
$setWindowFields: {
sortBy: {a: {$meta: "textScore"}},
output: {sum: {$sum: "$c", window: {documents: ["unbounded", "current"]}}}
}
},
{$sort: {a: {$meta: "textScore"}}},
]);
assert.eq(2, numberOfStages(explain13, '$sort'), explain13);
})();
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