db.collection.hideIndex()¶

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Definition
Syntax
Behavior
Access Control
Example

Definition¶

db.collection.hideIndex()¶

New in version 4.4.

mongo Shell Method

This page documents the mongo shell method, and does not refer to the MongoDB Node.js driver (or any other driver) method. For corresponding MongoDB driver API, refer to your specific MongoDB driver documentation instead.

Hides an existing index from the query planner. An index hidden from the query planner is not evaluated as part of query plan selection.

By hiding an index from the planner, users can evaluate the potential impact of dropping an index without actually dropping the index. If the impact is negative, the user can unhide the index instead of having to recreate a dropped index. And because indexes are fully maintained while hidden, the indexes are immediately available for use once unhidden.

For details, see Hidden Indexes.

Syntax¶

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db.collection.hideIndex(<index>)

Parameters¶

The db.collection.hideIndex() method takes the following parameter:

Parameter Type Description

index

string or document

Specifies the index to hide from the query planner. You can specify the index either by the index name or by the index specification document.

Tip

You can use the db.collection.getIndexes() method to find the index name or the index specification document.

To hide a text index, specify the index name.

The db.collection.hideIndex() is a mongo shell wrapper for the collMod command.

Behavior¶

Feature Compatibility Version¶

To hide an index, you must have featureCompatibilityVersion set to 4.4 or greater. However, once hidden, the index remains hidden even with featureCompatibilityVersion set to 4.2 on MongoDB 4.4 binaries.

Restrictions¶

You cannot hide the _id index.

Index Modifications Reset Statistics¶

Hiding an unhidden index resets its $indexStats.

No-op¶

Hiding an already hidden index has no effect on the index. However, the operation will still generate an empty oplog entry.

Access Control¶

If the deployment enforces authentication/authorization, you must have the collMod privilege in the collection’s database.

The built-in role dbAdmin provides the required privileges.

Example¶

The following example hides an existing index.

First, use db.collection.createIndex() to create an index without hiding:

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db.restaurants.createIndex( { borough: 1, ratings: 1 } );

To hide the index, you can specify either the index key specification document or the index name to the db.collection.hideIndex() method. The following specifies the index name:

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db.restaurants.hideIndex( "borough_1_ratings_1" );

To verify, run db.collection.getIndexes() on the restaurants collection:

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db.restaurants.getIndexes();

The operation returns the following information:

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[
   {
      "v" : 2,
      "key" : {
         "_id" : 1
      },
      "name" : "_id_"
   },
   {
      "v" : 2,
      "key" : {
         "borough" : 1,
         "ratings" : 1
      },
      "name" : "borough_1_ratings_1",
      "hidden" : true
   }
]

The hidden index option is only returned if the value is true.