MongoDB Query Plan Cache Commands
MongoDB planCacheClear command
The planCacheClear command is used to remove the cached query plans for a collection. It declares the query shape to remove the cached query plan for that shape.
We have the following query shape:
The following code clears the query plan cached for the shape:
MongoDB planCacheClearFilters command
The planCacheClearFilters command removes index filters on a collection. We can also clear existing index filters with this command while index filters only exist for the duration of the server process and don't persist after shutdown.
The books collection contains the following two filters:
The following command will remove the first index filter:
MongoDB planCacheListFilters command
The palncacheListFilters command lists the index filters associated with query shapes for a collection.
MongoDB palnCacheSetFilter command
This command set an index filter for a collection. It is the index filter that already exists for the query shape. The planCacheSetFilter overwrites the previous index filter.
The example creates an index filter on the books collection such that for queries that contains only of an equality match on the purchase field without any projection and sort.