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planCacheClear
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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
planCacheClearcommand has the following field:Field Type Description querydocument 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. projectiondocument Optional. The projection associated with the query shape. sortdocument Optional. The sort associated with the query shape. To see the query shapes for which cached query plans exist, use the
planCacheListQueryShapescommand.
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 }
}
)