planCacheSetFilter
Definition
planCacheSetFilter
Set an index filter for a collection. If an index filter already exists for the plan cache query shape, the command overrides the previous index filter.
Query Settings
New in version 8.0.
Starting in MongoDB 8.0, use query settings instead of adding index filters. Index filters are deprecated starting in MongoDB 8.0.
Query settings have more functionality than index filters. Also, index
filters aren't persistent and you cannot easily create index filters for
all cluster nodes. To add query settings and explore examples, see
setQuerySettings
.
The query optimizer uses the query settings as an additional input during query planning, which affects the plan selected to run the query.
The settings apply to the query shape on the entire cluster. The cluster retains the settings after shutdown.
You can add query settings for find
, distinct
,
and aggregate
commands.
To remove query settings, use removeQuerySettings
. To
obtain the query settings, use a $querySettings
stage in an
aggregation pipeline.
Compatibility
This command is available in deployments hosted in the following environments:
MongoDB Atlas: The fully managed service for MongoDB deployments in the cloud
Note
This command is not supported in M0, M2, and M5 clusters. For more information, see Unsupported Commands.
MongoDB Enterprise: The subscription-based, self-managed version of MongoDB
MongoDB Community: The source-available, free-to-use, and self-managed version of MongoDB
Syntax
The command has the following syntax:
db.runCommand( { planCacheSetFilter: <collection>, query: <query>, sort: <sort>, projection: <projection>, collation: { <collation> }, indexes: [ <index1>, <index2>, ...], comment: <any> } )
The plan cache query shape for the index filter is the combination of:
query
sort
projection
collation
Command Fields
The command has the following fields:
Field | Type | Description | ||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|
planCacheSetFilter | string | The name of the collection for the index filter. | ||||||||||
query | document | The query predicate for the index filter. Only the predicate structure, including the field names, is used in the index filter. The field values in the query predicate are not used. Therefore, the query predicate in an index filter is used by similar queries that differ only in the field values. | ||||||||||
sort | document | Optional. The sort for the index filter. | ||||||||||
projection | document | Optional. The projection for the index filter. | ||||||||||
collation | document | Specifies the collation to use for the operation. Collation allows users to specify language-specific rules for string comparison, such as rules for lettercase and accent marks. The collation option has the following syntax:
When specifying collation, the If the collation is unspecified but the collection has a
default collation (see If no collation is specified for the collection or for the operations, MongoDB uses the simple binary comparison used in prior versions for string comparisons. You cannot specify multiple collations for an operation. For example, you cannot specify different collations per field, or if performing a find with a sort, you cannot use one collation for the find and another for the sort. Starting in MongoDB 6.0, an index filter uses the collation previously set using the Starting in MongoDB 8.0, use query settings instead of adding index filters. Index filters are deprecated starting in MongoDB 8.0. Query settings have more functionality than index filters. Also, index
filters aren't persistent and you cannot easily create index filters for
all cluster nodes. To add query settings and explore examples, see
| ||||||||||
indexes | array | An array of index filters for the specified plan cache query shape. Specify the index filters as one of these arrays:
The query optimizer uses either a collection scan or the index arrays for the query plan. If the specified indexes do not exist or are hidden, the optimizer uses a collection scan. For multiple indexes with the same key pattern, you must specify the index as an array of names. | ||||||||||
comment | any | Optional. A user-provided comment to attach to this command. Once set, this comment appears alongside records of this command in the following locations:
A comment can be any valid BSON type (string, integer, object, array, etc). |
Index filters only exist for the duration of the server process and do
not persist after shutdown. To clear the index filters, use the
planCacheClearFilters
command.
Required Access
A user must have access that includes the
planCacheIndexFilter
action.
Examples
Set Filter on Plan Cache Query Shape Consisting of Predicate Only
The following example creates an index filter on the orders
collection such that for queries that consist only of an equality
match on the status
field without any projection and sort, the
query optimizer evaluates only the two specified indexes and the
collection scan for the winning plan:
db.runCommand( { planCacheSetFilter: "orders", query: { status: "A" }, indexes: [ { cust_id: 1, status: 1 }, { status: 1, order_date: -1 } ] } )
In the query predicate, only the structure of the predicate, including the field names, are significant; the values are insignificant. As such, the created filter applies to the following operations:
db.orders.find( { status: "D" } ) db.orders.find( { status: "P" } )
To see whether MongoDB will apply an index filter for a plan cache query shape,
check the indexFilterSet
field of either
the db.collection.explain()
or the cursor.explain()
method.
Set Filter on Plan Cache Query Shape Consisting of Predicate, Projection, and Sort
The following example creates an index filter for the orders
collection. The filter applies to queries whose predicate is an
equality match on the item
field, where only the quantity
field
is projected and an ascending sort by order_date
is specified.
db.runCommand( { planCacheSetFilter: "orders", query: { item: "ABC" }, projection: { quantity: 1, _id: 0 }, sort: { order_date: 1 }, indexes: [ { item: 1, order_date: 1 , quantity: 1 } ] } )
For the plan cache query shape, the query optimizer will only consider indexed
plans which use the index { item: 1, order_date: 1, quantity: 1 }
.
Set Filter on Plan Cache Query Shape Consisting of Predicate and Collation
The following example creates an index filter for the orders
collection. The filter applies to queries whose predicate is an equality
match on the item
field and the collation en_US
(English United
States).
db.runCommand( { planCacheSetFilter: "orders", query: { item: "Movie" }, collation: { locale: "en_US" }, indexes: [ { item: 1, order_date: 1 , quantity: 1 } ] } )
For the plan cache query shape, the query optimizer only uses indexed plans that
use the index { item: 1, order_date: 1, quantity: 1 }
.
Starting in MongoDB 6.0, an index filter uses the collation previously set using the planCacheSetFilter
command.
Starting in MongoDB 8.0, use query settings instead of adding index filters. Index filters are deprecated starting in MongoDB 8.0.
Query settings have more functionality than index filters. Also, index
filters aren't persistent and you cannot easily create index filters for
all cluster nodes. To add query settings and explore examples, see
setQuerySettings
.