Amazon DBS-C01 Practice Test - Questions Answers, Page 31

The correct answer is D. Create one table for each game. Use the player identifier as the partition key. Use the event time as the sort key.

The explanation is as follows:

The ItemCollectionSizeLimitExceededException error occurs when an item collection exceeds the 10 GB limit1. An item collection is a group of items that have the same partition key value but different sort key values2. In this case, the item collection is based on the game name, which has only three possible values. This means that all events for each game are stored in the same item collection, which can easily exceed the 10 GB limit given the high volume and size of events.

To avoid this error, a database specialist should recommend a design change that distributes the events across more partitions and reduces the size of each item collection. Option D achieves this by creating one table for each game, and using the player identifier as the partition key. This way, each event is stored in a separate partition based on the player identifier, and sorted by the event time. This design also supports efficient queries by game, player, and time range.

Option A is incorrect because it still uses a single table for all events, which can cause hot partitions and throttling due to uneven access patterns across games. Also, using the player identifier as the partition key can result in many small partitions that are underutilized and waste provisioned capacity. Adding a global secondary index with the game name as the partition key and the event time as the sort key does not solve the problem of item collection size limit, because global secondary indexes have their own item collections that are subject to the same limit3.

Option B is incorrect because it creates two tables with redundant data and increases storage costs. Also, using the game name as the partition key in both tables does not solve the problem of item collection size limit, as explained above.

Option C is incorrect because it still uses a single table for all events, which can cause hot partitions and throttling due to uneven access patterns across games. Also, replacing the sort key with a compound value consisting of the player identifier collated with the event time does not reduce the size of each item collection, because each event still has a unique sort key value. Adding a local secondary index with the player identifier as the sort key does not solve the problem of item collection size limit, because local secondary indexes share the same item collections as their base table4.

The correct answer is A. Add an inbound security group rule to the database security group that allows access from the developer account VPC CIDR on port 5432. Add an outbound security group rule to the EC2 security group that allows access to the production account VPC CIDR on port 5432. The explanation is as follows: To allow the reporting application to access the production database, the database administrator needs to configure the security group rules for both the database and the EC2 instance. The security group rules must allow traffic between the peered VPCs on the port that the database uses, which is 5432 for PostgreSQL1. Option A is correct because it adds an inbound rule to the database security group that allows access from the developer account VPC CIDR on port 5432. This means that the database can accept connections from the EC2 instance in the peered VPC. It also adds an outbound rule to the EC2 security group that allows access to the production account VPC CIDR on port 5432. This means that the EC2 instance can initiate connections to the database in the peered VPC. Option B is incorrect because it adds an outbound rule to the database security group, which is not necessary. The database does not need to initiate connections to the EC2 instance, only accept them. It also does not add an inbound rule to the EC2 security group, which is not required. The EC2 instance does not need to accept connections from the database, only initiate them. Option C is incorrect because it adds an inbound rule to the database security group that allows access from the developer account VPC CIDR on all TCP ports. This is too permissive and violates the principle of least privilege2. It also adds an inbound rule to the EC2 security group that allows access to the production account VPC CIDR on port 5432. This is unnecessary and does not help with connectivity. Option D is incorrect because it adds an outbound rule to the EC2 security group that allows access to the production account VPC CIDR on all TCP ports. This is too permissive and violates the principle of least privilege2. It also does not add an outbound rule to the database security group, which is not needed.

Option B is correct because it is the simplest and fastest way to migrate an Amazon RDS DB instance to another AWS account.Creating a DB snapshot of the DB instance captures the data and configuration of the DB instance at a point in time1.Sharing the snapshot with the destination AWS account allows the other account to access and restore the snapshot2.Creating a new DB instance by restoring the snapshot in the destination AWS account creates a copy of the original DB instance with the same data and configuration3. This solution requires minimal operational effort and downtime.

Option D is correct because it meets the requirements of securely accessing a DynamoDB table from EC2 instances in a hybrid environment.A VPC endpoint for DynamoDB enables EC2 instances in a VPC to use their private IP addresses to access DynamoDB with no exposure to the public internet1. The EC2 instances do not require public IP addresses, and do not need an internet gateway, a NAT device, or a virtual private gateway in the VPC. The endpoint policy and the security groups of the EC2 instances can control access to DynamoDB. Traffic between the VPC and DynamoDB does not leave the Amazon network. Assigning the endpoint to the route table of the private subnets that contain the EC2 instances ensures that any requests to DynamoDB from those subnets are routed to the private endpoint within the Amazon network.

Option A is correct because it sets the audit_logs cluster parameter to enabled.This enables auditing on the DocumentDB cluster, which records events that were performed in the cluster, such as successful and failed authentication attempts, dropping a collection in a database, or creating an index1. By enabling auditing, the database specialist can review the logs to see who and when deleted the primary DocumentDB database, and what other actions were taken on the cluster.

Option B is correct because it enables DocumentDB log export to Amazon CloudWatch Logs.This allows the DocumentDB cluster to export its auditing records (JSON documents) to Amazon CloudWatch Logs, where they can be analyzed, monitored, and archived1. By enabling log export, the database specialist can access the logs even if the primary DocumentDB database is deleted, as they are stored in a separate service.

Option C is correct because it solves the throttling issue without requiring changes to the app. On-demand capacity mode is a flexible billing option for DynamoDB that automatically accommodates your workload as it ramps up or down. With on-demand mode, you pay per request for the data reads and writes your application performs on your tables, and you don't need to specify how much read and write throughput you expect.On-demand mode can handle sudden increases and decreases in activity without throttling, as long as the request rate does not exceed the default table quotas1.To use on-demand mode, you only need to update the table settings in the AWS Management Console or by using the AWS SDK2. You don't need to modify any application logic, as on-demand mode is compatible with existing DynamoDB API calls.