PlanCache.clearPlansByQuery()

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Definition

  • 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:

ParameterTypeDescription
querydocumentThe 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.
projectiondocumentOptional. The projection associated with the query shape. Required if specifying the sort parameter.
sortdocumentOptional. The sort associated with the query shape.

To see the query shapes for which cached query plans exist, use the PlanCache.listQueryShapes() method.

Required Access

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

Example

If a collection orders has the following query shape:

{
  "query" : { "qty" : { "$gt" : 10 } },
  "sort" : { "ord_date" : 1 },
  "projection" : { }
}

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

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