PlanCache.clearPlansByQuery() (mongosh method)

Definition

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

Clears the cached query plans for the specified 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 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 query shape. Required if specifying the sort parameter.
sort	document	Optional. The sort associated with the 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.

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 },
  "collation" : { locale : "fr" },
  "projection" : { },
  "queryHash" : "9AAD95BE"
}

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

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