db.collection.getPlanCache()

On this page本页内容

Definition定义

db.collection.getPlanCache()

mongo Shell Method

This page documents the mongo shell method, and does not refer to the MongoDB Node.js driver (or any other driver) method. 本页记录了mongo shell方法,未提及MongoDB Node.js驱动程序(或任何其他驱动程序)方法。For corresponding MongoDB driver API, refer to your specific MongoDB driver documentation instead.有关相应的MongoDB驱动程序API,请参阅特定的MongoDB驱动程序文档。

Returns an interface to access the query plan cache for a collection. 返回访问集合的查询计划缓存的接口。The interface provides methods to view and clear the query plan cache.该接口提供了查看和清除查询计划缓存的方法。

Returns:返回:Interface to access the query plan cache.接口来访问查询计划缓存。

The query optimizer only caches the plans for those query shapes that can have more than one viable plan.查询优化器只缓存那些可以有多个可行计划的查询形状的计划。

Methods方法

The following methods are available through the interface:通过该接口可以使用以下方法:

Name名称Description描述
PlanCache.help() Displays the methods available for a collection’s query plan cache. 显示集合的查询计划缓存可用的方法。Accessible through the plan cache object of a specific collection, i.e. db.collection.getPlanCache().help().可通过特定集合的plan cache对象访问,即db.collection.getPlanCache().help()
PlanCache.clearPlansByQuery() Clears the cached query plans for the specified query shape. 清除指定查询形状的缓存查询计划。Accessible through the plan cache object of a specific collection, i.e. db.collection.getPlanCache().clearPlansByQuery()可通过特定集合的计划缓存对象访问,即db.collection.getPlanCache().clearPlansByQuery()
PlanCache.clear() Clears all the cached query plans for a collection. 清除集合的所有缓存查询计划。Accessible through the plan cache object of a specific collection, i.e. db.collection.getPlanCache().clear().可通过特定集合的plan cache对象访问,即db.collection.getPlanCache().clear()
PlanCache.list()

Returns the plan cache information for a collection. 返回集合的计划缓存信息。Accessible through the plan cache object of a specific collection, i.e. db.collection.getPlanCache().list().可通过特定集合的计划缓存对象访问,即db.collection.getPlanCache().list()

New in version 4.4.版本4.4中的新功能。