OPTIONS

planCacheClear

Definition

planCacheClear

New in version 2.6.

Removes cached query plans for a collection. Specify a query shape to remove cached query plans for that shape. Omit the query shape to clear all cached query plans.

The command has the following syntax:

db.runCommand(
   {
      planCacheClear: <collection>,
      query: <query>,
      sort: <sort>,
      projection: <projection>
   }
)

The planCacheClear command has the following field:

Field Description
query Optional. 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 Optional. The projection associated with the query shape.
sort Optional. The sort associated with the query shape.

To see the query shapes for which cached query plans exist, use the planCacheListQueryShapes command.

Required Access

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

Examples

Clear Cached Plans for a Query Shape

If a collection orders has the following query shape:

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

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

db.runCommand(
   {
      planCacheClear: "orders",
      query: { "qty" : { "$gt" : 10 } },
      sort: { "ord_date" : 1 }
   }
)

Clear All Cached Plans for a Collection

The following example clears all the cached query plans for the orders collection:

db.runCommand(
   {
      planCacheClear: "orders"
   }
)