PlanCache.clearPlansByQuery()¶

Definition定义¶

PlanCache.clearPlansByQuery(<query>, <projection>, <sort>)¶

Clears the cached query plans for the specified query shape.

The method is only available from the plan cache object of a specific collection; i.e.

db.collection.getPlanCache().clearPlansByQuery( <query>, <projection>, <sort> )

The PlanCache.clearPlansByQuery() method accepts the following parameters:

Parameter参数	Type类型	Description描述
query	document	The query predicate of the query shape. Only the structure of the predicate, including the field names, are significant to the shape; the values in the query predicate are insignificant.
projection	document	Optional.可选。The projection associated with the query shape. Required if specifying the sort parameter.
sort	document	Optional.可选。The sort associated with the query shape.

To see the query shapes for which cached query plans exist, see List Query Shapes.

Required Access¶

On systems running with authorization, a user must have access that includes the planCacheWrite action.

Example示例¶

If a collection orders has the following query shape:

{
  "query" : { "qty" : { "$gt" : 10 } },
  "sort" : { "ord_date" : 1 },
  "projection" : { },
  "queryHash" : "9AAD95BE" // Available starting in MongoDB 4.2
}

The following operation removes the query plan cached for the shape:

db.orders.getPlanCache().clearPlansByQuery(
   { "qty" : { "$gt" : 10 } },
   { },
   { "ord_date" : 1 }
)