mongo/jstests/libs/query/cbr_utils.js

53 lines
1.6 KiB
JavaScript

/**
* Utilities for writing tests for the cost-based ranker (CBR).
*/
// Round the given number to the nearest 0.1
function round(num) {
return Math.round(num * 10) / 10;
}
// Compare two cardinality estimates with approximate equality. This is done so that our tests can
// be robust to floating point rounding differences but detect large changes in estimation
// indicating a real change in estimation behavior.
export function ceEqual(lhs, rhs) {
return Math.abs(round(lhs) - round(rhs)) < 0.1;
}
function planEstimateTypeIs(plan, type) {
return plan.estimatesMetadata.ceSource === type;
}
// Return true if the plan was estimated with a histogam estimation source. Return false otherwise.
export function planEstimatedWithHistogram(plan) {
return planEstimateTypeIs(plan, "Histogram");
}
/**
* Assert the given plan was not costed. This is used as an indicator to whether CBR used its
* fallback to multiplanning for this plan.
*/
export function assertPlanNotCosted(plan) {
assert(!plan.hasOwnProperty("costEstimate"), plan);
}
/**
* Assert the given plan was costed.
*/
export function assertPlanCosted(plan) {
assert(plan.hasOwnProperty("costEstimate"), plan);
}
export function getPlanRankerMode(db) {
if (db !== null) {
const getParam = db.adminCommand({
getParameter: 1,
planRankerMode: 1,
});
return getParam.hasOwnProperty("planRankerMode") ? getParam.planRankerMode : "multiPlanning";
} else {
return TestData.setParameters.planRankerMode ? TestData.setParameters.planRankerMode : "multiPlanning";
}
}