PlanCache.clearPlansByQuery() (mongosh method)

Definition

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

Clears the cached query plans for the specified plan cache query shape.

Important

mongosh Method

This page documents a mongosh method. This is not the documentation for database commands or language-specific drivers, such as Node.js.

For the database command, see the planCacheClear command.

For MongoDB API drivers, refer to the language-specific MongoDB driver documentation.

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

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

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

Parameter	Type	Description
query	document	The query predicate of the plan cache 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. The projection associated with the plan cache query shape. Required if specifying the sort parameter.
sort	document	Optional. The sort associated with the plan cache query shape.
collation	document	Optional. Specifies the collation to use for the operation. Collation allows users to specify language-specific rules for string comparison, such as rules for lettercase and accent marks. The collation option has the following syntax: collation: { locale: <string>, caseLevel: <boolean>, caseFirst: <string>, strength: <int>, numericOrdering: <boolean>, alternate: <string>, maxVariable: <string>, backwards: <boolean> } When specifying collation, the locale field is mandatory; all other collation fields are optional. For descriptions of the fields, see Collation Document. If the collation is unspecified but the collection has a default collation (see db.createCollection()), the operation uses the collation specified for the collection. If no collation is specified for the collection or for the operations, MongoDB uses the simple binary comparison used in prior versions for string comparisons. You cannot specify multiple collations for an operation. For example, you cannot specify different collations per field, or if performing a find with a sort, you cannot use one collation for the find and another for the sort.

To see the query shapes for which cached query plans exist, see Examples.

Starting in MongoDB 8.0, use query settings instead of adding index filters. Index filters are deprecated starting in MongoDB 8.0.

Query settings have more functionality than index filters. Also, index filters aren't persistent and you cannot easily create index filters for all cluster nodes. To add query settings and explore examples, see setQuerySettings.

Compatibility

This method is available in deployments hosted in the following environments:

• MongoDB Atlas: The fully managed service for MongoDB deployments in the cloud

• MongoDB Enterprise: The subscription-based, self-managed version of MongoDB

• MongoDB Community: The source-available, free-to-use, and self-managed version of MongoDB

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 plan cache query shape:

{
  "query" : { "qty" : { "$gt" : 10 } },
  "sort" : { "ord_date" : 1 },
  "collation" : { locale : "fr" },
  "projection" : { },
  "planCacheShapeHash" : "9AAD95BE"
}

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

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