Amazon DynamoDB
API Reference (API Version 2012-08-10)


Represents a single element of a key schema. A key schema specifies the attributes that make up the primary key of a table, or the key attributes of an index.

A KeySchemaElement represents exactly one attribute of the primary key. For example, a simple primary key would be represented by one KeySchemaElement (for the partition key). A composite primary key would require one KeySchemaElement for the partition key, and another KeySchemaElement for the sort key.

A KeySchemaElement must be a scalar, top-level attribute (not a nested attribute). The data type must be one of String, Number, or Binary. The attribute cannot be nested within a List or a Map.



In the following list, the required parameters are described first.


The name of a key attribute.

Type: String

Length Constraints: Minimum length of 1. Maximum length of 255.

Required: Yes


The role that this key attribute will assume:

  • HASH - partition key

  • RANGE - sort key


The partition key of an item is also known as its hash attribute. The term "hash attribute" derives from DynamoDB' usage of an internal hash function to evenly distribute data items across partitions, based on their partition key values.

The sort key of an item is also known as its range attribute. The term "range attribute" derives from the way DynamoDB stores items with the same partition key physically close together, in sorted order by the sort key value.

Type: String

Valid Values: HASH | RANGE

Required: Yes