How do you set the primary key in DynamoDB?

There are two ways to set a primary key in DynamoDB: a simple primary key consisting of a single attribute, and a composite primary key consisting of two attributes.

1. Simple Primary Key: A primary key composed of a single attribute. When creating a table, one attribute can be designated as the primary key. The value of this attribute must be unique and cannot be null. A simple primary key consists of only one attribute, which can be a string, number, or binary type.
2. Composite Primary Key: A primary key composed of two attributes. When creating a table, you can specify two attributes as a composite primary key. The first attribute is called the partition key, and the second attribute is called the sort key. A composite primary key can be used to build a relationship model for partitioning and sorting to support query and sorting needs.

Whether it is a simple primary key or a composite primary key, the selection of the primary key should be based on the data access patterns and query requirements. Choosing the appropriate primary key design based on the data’s read/write patterns and query needs can optimize data access performance and query efficiency.