Why batch operations improve efficiency in DynamoDB

Introduction

Batch operations let you handle many items at once, saving time and effort. This makes your database work faster and uses fewer resources.

When you need to add many new items to your database quickly.

When you want to update several records at the same time.

When you want to delete multiple items without sending many separate requests.

When you want to read many items in one go to reduce waiting time.

When you want to reduce the number of calls to the database to save costs.

Syntax

DynamoDB

BatchWriteItem {
  RequestItems: {
    "TableName": [
      { PutRequest: { Item: {...} } },
      { DeleteRequest: { Key: {...} } }
    ]
  }
}

BatchGetItem {
  RequestItems: {
    "TableName": {
      Keys: [{...}, {...}],
      ProjectionExpression: "attribute1, attribute2"
    }
  }
}

BatchWriteItem can include both PutRequest (to add) and DeleteRequest (to remove) in one call.

BatchGetItem lets you request multiple items by their keys in a single call.

Examples

This example adds one book and deletes another in one batch call.

DynamoDB

BatchWriteItem {
  RequestItems: {
    "Books": [
      { PutRequest: { Item: { "ISBN": "123", "Title": "Book A" } } },
      { DeleteRequest: { Key: { "ISBN": "456" } } }
    ]
  }
}

This example fetches the title and author of two books in one request.

DynamoDB

BatchGetItem {
  RequestItems: {
    "Books": {
      Keys: [
        { "ISBN": "123" },
        { "ISBN": "789" }
      ],
      ProjectionExpression: "Title, Author"
    }
  }
}

Sample Program

This program adds two users in one batch write, then reads their names in one batch get.

DynamoDB

BatchWriteItem {
  RequestItems: {
    "Users": [
      { PutRequest: { Item: { "UserID": "u1", "Name": "Alice" } } },
      { PutRequest: { Item: { "UserID": "u2", "Name": "Bob" } } }
    ]
  }
}

BatchGetItem {
  RequestItems: {
    "Users": {
      Keys: [
        { "UserID": "u1" },
        { "UserID": "u2" }
      ],
      ProjectionExpression: "Name"
    }
  }
}

Important Notes

Batch operations reduce the number of network calls, which speeds up your app.

There are limits on how many items you can include in one batch, so check the service rules.

Batch operations are atomic per item but not across the whole batch, so some items may succeed while others fail.

Summary

Batch operations group many actions into one request to save time.

They reduce network calls and improve speed.

Use batch operations when working with many items at once.