WebJun 19, 2024 · MongoDB, when faced with a query, needs to determine a reasonable strategy for executing the query. This is a black art in any good database system, since … WebMongoDB 提供了几种方法用于返回执行计划和执行计划统计信息，它们是： db.collection.explain() 方法； cursor.explain() 方法； explain 命令； 本篇我们讨论的是 cursor.explain() 方法，以下简称 explain()，其语法如下： db.collection.find().explain()
Analyze Query Performance — MongoDB Manual
WebThe explain plan results for queries are subject to change between MongoDB versions. MongoDB Shell Compass The cursor.explain ("executionStats") and the … WebMar 7, 2024 · In the Mongo universe, the explain () method returns a document along with the information on the query plan. This method has the following prototype form: Mongo database ‘explain ()’ Syntax. 1. > db.collection_name.explain () Where: The verbosity_parameter is an optional string value that specifies the verbosity … gtin explained
Does MongoDB stages should avoid FETCH when INDEX is …
Webexplain.queryPlanner.planCacheKey A hash of the key for the plan cache entry associated with the query. Unlike the queryHash, the planCacheKeyis a function of both the query … WebSep 18, 2024 · If you are not familiar with using explain() with simple find() queries, see this post or check out the MongoDB documentation. To use explain, we add the .explain() method after the collection name: WebJun 19, 2024 · Running explain() in MongoDB When you run explain() in MongoDB, some knowledge is required to understand the actual results that the function returns. A core concept of MongoDB queries is the "winning plan." Whenever the query optimizer runs queries, it selects its execution plan from an array of available indexes—different plans. … gtin exemption support letter for brand