Batch Delete Using DynamoDB Mapper (Guide w/ Code Examples)

Use BatchWriteItem with DeleteRequest entries to delete items whose full keys you already know. Retry only the returned UnprocessedItems; the whole batch is not atomic.

DynamoDBMapper belongs to AWS SDK for Java 1.x and cannot be constructed with a 2.x DynamoDbClient. The example below shows the SDK 2.x low-level equivalent. For mapped domain objects, use the DynamoDB Enhanced Client.

This example uses Java 17+ and the software.amazon.awssdk:dynamodb SDK 2.x dependency. Configure an AWS Region and credentials through your usual AWS profile or runtime role. The Orders table has String keys pk and sk; adapt the table and keys to your schema.

import java.util.*;
import software.amazon.awssdk.services.dynamodb.DynamoDbClient;
import software.amazon.awssdk.services.dynamodb.model.*;

public class Example {
    static AttributeValue s(String value) { return AttributeValue.builder().s(value).build(); }
    static Map<String, AttributeValue> key(String order) {
        return Map.of("pk", s("CUSTOMER#123"), "sk", s(order));
    }

    public static void main(String[] args) throws InterruptedException {
        try (DynamoDbClient ddb = DynamoDbClient.create()) {
            List<WriteRequest> writes = new ArrayList<>();
            for (String order : List.of("ORDER#001", "ORDER#002")) {
                writes.add(WriteRequest.builder().deleteRequest(DeleteRequest.builder().key(key(order)).build()).build());
            }
            Map<String, List<WriteRequest>> pending = Map.of("Orders", writes);
            for (int attempt = 0; !pending.isEmpty(); attempt++) {
                if (attempt == 8) throw new IllegalStateException("Unprocessed writes: " + pending);
                if (attempt > 0) Thread.sleep((long) (Math.random() * Math.min(5000L, 100L << attempt)));
                pending = ddb.batchWriteItem(BatchWriteItemRequest.builder()
                    .requestItems(pending).build()).unprocessedItems();
            }
        }
    }
}

Each batch supports at most 25 put/delete operations. Batch deletes cannot use conditions; use DeleteItem or transactions if deletion depends on the current item state.

Reference: AWS BatchWriteItem API. For related access patterns, see DynamoDB query examples.