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- mongo Shell Methods >
- Query Plan Cache Methods >
- db.collection.getPlanCache()
db.collection.getPlanCache()¶
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Definition¶
- db.collection.getPlanCache()¶
Returns an interface to access the query plan cache for a collection. The interface provides methods to view and clear the query plan cache.
返回: Interface to access the query plan cache. The query optimizer only caches the plans for those query shapes that can have more than one viable plan.
Methods¶
The following methods are available through the interface:
| Name | Description |
|---|---|
| PlanCache.help() | Displays the methods available for a collection’s query plan cache. Accessible through the plan cache object of a specific collection, i.e. db.collection.getPlanCache().help(). |
| PlanCache.listQueryShapes() | Displays the query shapes for which cached query plans exist. Accessible through the plan cache object of a specific collection, i.e. db.collection.getPlanCache().listQueryShapes(). |
| PlanCache.getPlansByQuery() | Displays the cached query plans for the specified query shape. Accessible through the plan cache object of a specific collection, i.e. db.collection.getPlanCache().getPlansByQuery(). |
| PlanCache.clearPlansByQuery() | Clears the cached query plans for the specified query shape. Accessible through the plan cache object of a specific collection, i.e. db.collection.getPlanCache().clearPlansByQuery() |
| PlanCache.clear() | Clears all the cached query plans for a collection. Accessible through the plan cache object of a specific collection, i.e. db.collection.getPlanCache().clear(). |