> For the complete MongoDB documentation index, see www.mongodb.com/docs/llms.txt

# planCacheClear (database command)

## Definition

Removes cached query plans for a collection. Specify a [plan cache query shape](https://www.mongodb.com/docs/manual/reference/glossary.md#std-term-plan-cache-query-shape) to remove cached query plans for that shape. Omit the plan cache query shape to clear all cached query plans.

**Tip:**

In [`mongosh`](https://www.mongodb.com/docs/mongodb-shell.md#std-program-mongosh), this command can also be run through the [`PlanCache.clear()`](https://www.mongodb.com/docs/manual/reference/method/plancache.clear.md#mongodb-method-PlanCache.clear) and
[`PlanCache.clearPlansByQuery()`](https://www.mongodb.com/docs/manual/reference/method/plancache.clearplansbyquery.md#mongodb-method-PlanCache.clearPlansByQuery) helper methods.

Helper methods are convenient for [`mongosh`](https://www.mongodb.com/docs/mongodb-shell.md#std-program-mongosh) users, but they may not return the same level of information as database commands.  In cases where the convenience is not needed or the additional return fields are required, use the database command.

### Query Settings

Starting in MongoDB 8.0, use query settings instead of adding [index filters](https://www.mongodb.com/docs/manual/core/query-plans.md#std-label-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`.](https://www.mongodb.com/docs/manual/reference/command/setquerysettings.md#mongodb-dbcommand-dbcmd.setQuerySettings)

## Compatibility

This command is available in deployments hosted in the following environments:

- [MongoDB Atlas](https://www.mongodb.com/docs/atlas): The fully managed service for MongoDB deployments in the cloud

**Important:**

This command is not supported in M0 and Flex clusters. For more information, see [Unsupported Commands.](https://www.mongodb.com/docs/atlas/unsupported-commands/)

- [MongoDB Enterprise](https://www.mongodb.com/docs/manual/administration/install-enterprise.md#std-label-install-mdb-enterprise): The subscription-based, self-managed version of MongoDB

- [MongoDB Community](https://www.mongodb.com/docs/manual/administration/install-community.md#std-label-install-mdb-community-edition): The source-available, free-to-use, and self-managed version of MongoDB

## Syntax

The command has the following syntax:

```javascript
db.runCommand(
   {
      planCacheClear: <collection>,
      query: <query>,
      sort: <sort>,
      collation: <collation>,
      projection: <projection>,
      comment: <any>
   }
)
```

## Command Fields

The command takes the following optional fields:

| Field | Type | Description |
| --- | --- | --- |
| `query` | document | Optional. The query predicate of the plan cache 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. |
| `projection` | document | Optional. The projection associated with the plan cache query shape. |
| `sort` | document | Optional. The sort associated with the plan cache query shape. |
| `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: [mongod log messages](https://www.mongodb.com/docs/manual/reference/log-messages.md#std-label-log-messages-ref), in the `attr.command.cursor.comment` field.; [Database profiler](https://www.mongodb.com/docs/manual/reference/database-profiler.md#std-label-profiler) output, in the [`command.comment`](https://www.mongodb.com/docs/manual/reference/database-profiler.md#mongodb-data-system.profile.command) field.; [`currentOp`](https://www.mongodb.com/docs/manual/reference/command/currentop.md#mongodb-dbcommand-dbcmd.currentOp) output, in the [`command.comment`](https://www.mongodb.com/docs/manual/reference/command/currentop.md#mongodb-data-currentOp.command) field. A comment can be any valid [BSON type](https://www.mongodb.com/docs/manual/reference/bson-types.md#std-label-bson-types) (string, integer, object, array, etc). |
| `collation` | document | Optional. Specifies the [collation](https://www.mongodb.com/docs/manual/reference/collation.md#std-label-collation)  to use for the operation. [Collation](https://www.mongodb.com/docs/manual/reference/collation.md#std-label-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: `collation: {
    locale: <string>,
    caseLevel: <boolean>,
    caseFirst: <string>,
    strength: <int>,
    numericOrdering: <boolean>,
    alternate: <string>,
    maxVariable: <string>,
    backwards: <boolean>
 }` When specifying collation, the `locale` field is mandatory; all other collation fields are optional. For descriptions of the fields, see [Collation Document.](https://www.mongodb.com/docs/manual/reference/collation.md#std-label-collation-document-fields) If the collation is unspecified but the collection has a default collation (see [`db.createCollection()`](https://www.mongodb.com/docs/manual/reference/method/db.createcollection.md#mongodb-method-db.createCollection)), the operation uses the collation specified for the collection. 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. |

To see the query shapes for which cached query plans exist, see [Examples.](https://www.mongodb.com/docs/manual/reference/operator/aggregation/plancachestats.md#std-label-planCacheStats-examples)

## Required Access

On systems running with [`authorization`](https://www.mongodb.com/docs/manual/reference/configuration-options.md#mongodb-setting-security.authorization), a user must have access that includes the [`planCacheWrite`](https://www.mongodb.com/docs/manual/reference/privilege-actions.md#mongodb-authaction-planCacheWrite) action.

## Examples

### Clear Cached Plans for a Plan Cache Query Shape

If a collection `orders` has the following plan cache query shape:

```javascript
{
  "query" : { "qty" : { "$gt" : 10 } },
  "sort" : { "ord_date" : 1 },
  "collation" : { locale : "fr" },
  "projection" : { },
  "planCacheShapeHash" : "9AAD95BE"
}
```

**Warning:**

Starting in MongoDB 8.0, the existing `queryHash` field is duplicated in a new field named `planCacheShapeHash`. If you're using an earlier MongoDB version, you'll only see the `queryHash` field. Future MongoDB versions will remove the deprecated `queryHash` field, and you'll need to use the `planCacheShapeHash` field instead.

The following operation clears the query plan cached for the shape:

```javascript
db.runCommand(
   {
      planCacheClear: "orders",
      query: { "qty" : { "$gt" : 10 } },
      sort: { "ord_date" : 1 },
      collation: { locale : "fr" }
   }
)
```

### Clear All Cached Plans for a Collection

The following example clears all the cached query plans for the `orders` collection:

```javascript
db.runCommand(
   {
      planCacheClear: "orders"
   }
)
```

**See also:**

- [`PlanCache.clearPlansByQuery()`](https://www.mongodb.com/docs/manual/reference/method/plancache.clearplansbyquery.md#mongodb-method-PlanCache.clearPlansByQuery)

- [`PlanCache.clear()`](https://www.mongodb.com/docs/manual/reference/method/plancache.clear.md#mongodb-method-PlanCache.clear)