Why IAM policies protect data in DynamoDB

Introduction

IAM policies control who can access your data and what they can do with it. This keeps your data safe from unwanted changes or viewing.

When you want to allow only certain team members to read or write data.

When you need to prevent accidental deletion of important data.

When you want to give temporary access to a partner or service.

When you want to track who accessed or changed your data.

When you want to follow security rules for your company or law.

Syntax

DynamoDB

{
  "Version": "2012-10-17",
  "Statement": [
    {
      "Effect": "Allow" /* or "Deny" */,
      "Action": "dynamodb:ActionName",
      "Resource": "arn:aws:dynamodb:region:account-id:table/TableName"
    }
  ]
}

IAM policies use JSON format to define permissions clearly.

You specify actions like reading or writing and the exact table to protect.

Examples

This policy lets a user read items from the 'Books' table only.

DynamoDB

{
  "Effect": "Allow",
  "Action": "dynamodb:GetItem",
  "Resource": "arn:aws:dynamodb:us-east-1:123456789012:table/Books"
}

This policy blocks deleting items from the 'Books' table.

DynamoDB

{
  "Effect": "Deny",
  "Action": "dynamodb:DeleteItem",
  "Resource": "arn:aws:dynamodb:us-east-1:123456789012:table/Books"
}

Sample Program

This IAM policy allows reading and writing items in the 'Library' table but denies deleting any items. It protects data by controlling exactly what actions are allowed.

DynamoDB

{
  "Version": "2012-10-17",
  "Statement": [
    {
      "Effect": "Allow",
      "Action": ["dynamodb:GetItem", "dynamodb:PutItem"],
      "Resource": "arn:aws:dynamodb:us-east-1:123456789012:table/Library"
    },
    {
      "Effect": "Deny",
      "Action": "dynamodb:DeleteItem",
      "Resource": "arn:aws:dynamodb:us-east-1:123456789012:table/Library"
    }
  ]
}

Important Notes

Always use the least privilege principle: give only the permissions needed.

Test your policies carefully to avoid accidentally blocking needed access.

Combine Allow and Deny statements to fine-tune access control.

Summary

IAM policies protect data by controlling who can do what.

They use JSON to specify allowed or denied actions on specific tables.

Proper policies keep your data safe and help follow security rules.