db.collection.analyzeShardKey()

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Definition

Syntax
Fields
Behavior
Access Control
Output
Examples
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Definition

db.collection.analyzeShardKey(key, options): Calculates metrics for evaluating a shard key for an unsharded or sharded collection. Metrics are based on sampled queries. You can use configureQueryAnalyzer to configure query sampling on a collection.

Syntax

db.collection.analyzeShardKey() has this syntax:

db.collection.analyzeShardKey(
   {
     key: <shardKey>,
     keyCharacteristics: <bool>,
     readWriteDistribution: <bool>,
     sampleRate: <double>,
     sampleSize: <int>
   }
 )

Fields

Field	Type	Necessity	Description
`key`	document	Required	Shard key to analyze. This can be a candidate shard key for an unsharded collection or sharded collection or the current shard key for a sharded collection. There is no default value.
`keyCharacteristics`	boolean	Optional	Whether or not the metrics about the characteristics of the shard key are calculated. For details, see keyCharacteristics. Defaults to `true`.
`readWriteDistribution`	boolean	Optional	Whether or not the metrics about the read and write distribution are calculated. For details, see readWriteDistribution. Defaults to `true`.
`sampleRate`	double	Optional	The proportion of the documents in the collection to sample when calculating the metrics about the characteristics of the shard key. If you set `sampleRate`, you cannot set `sampleSize`. Must greater than `0`, up to and including `1`. There is no default value.
`sampleSize`	integer	Optional	The number of documents to sample when calculating the metrics about the characteristics of the shard key. If you set `sampleSize`, you cannot set `sampleRate`. If not specified and `sampleRate` is not specified, the sample size defaults to sample size set by `analyzeShardKeyCharacteristicsDefaultSampleSize`.

Behavior

For behavior, see analyzeShardKey Behavior.

Access Control

For details, see analyzeShardKey Access Control.

Output

For sample output, see analyzeShardKey Output.

Examples

For examples, see analyzeShardKey Examples.

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Collection Methods

db.collection.aggregate()