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PlanCache.listQueryShapes()
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Definition
PlanCache.
listQueryShapes
( )-
Displays the query shapes for which cached query plans exist.
The query optimizer only caches the plans for those query shapes that can have more than one viable plan.
The method is only available from the
plan cache object
of a specific collection; i.e.db.collection.getPlanCache().listQueryShapes()
Returns: Array of query shape documents. The method wraps the
planCacheListQueryShapes
command.
Required Access
On systems running with authorization
, a user must have access that includes the planCacheRead
action.
Example
The following returns the query shapes that have cached plans for the orders
collection:
db.orders.getPlanCache().listQueryShapes()
The method returns an array of the query shapes currently in the cache. In the example, the orders
collection had cached query plans associated with the following shapes:
[
{
"query" : { "qty" : { "$gt" : 10 } },
"sort" : { "ord_date" : 1 },
"projection" : { }
},
{
"query" : { "$or" :
[
{ "qty" : { "$gt" : 15 }, "item" : "xyz123" },
{ "status" : "A" }
]
},
"sort" : { },
"projection" : { }
},
{
"query" : { "$or" : [ { "qty" : { "$gt" : 15 } }, { "status" : "A" } ] },
"sort" : { },
"projection" : { }
}
]
Note
Not all queries automatically place a query plan in the cache. db.collection.getPlanCache().listQueryShapes()
returns an empty array if there are currently no query shapes with cached query plans.