Cloud Certifications: AWS Certified Database - Specialty

Introduction The database is the most significant and widely used feature in the software industry. Data is one of the core entities in app design and architecture. Often apps are developed using data-driven techniques like domain-driven design (DDD) where the focus is on data objects and entities. Data plays a prominent role in app development and cloud computing.

AWS offers various SQL and No-SQL database services for storage with additional features like events, load-balancing, security, logging, backup/recovery, and failover support. These services and resources can be configured easily with AWS Systems Manager to facilitate instant development setup with automatic maintenance support for OS/software version updates, patches, etc.

The AWS Certified Database - Specialty certification focuses on deep concepts of databases and their critical aspects such as designing, security, configuration, deployment, migration, monitoring, automation, and troubleshooting. This certification is for experienced database developers to achieve a badge of excellence in AWS database development.

This guide covers the important details of the AWS Certified Database - Specialty certification and provides tips and recommended resources with in-depth details.

The AWS Certified Database - Specialty certification primarily focuses on the AWS database for collection, storage, processing, and visualization services with the best practices using available tools. This includes services:

S3, or Simple Storage Service, stores data as an object. S3 data objects are stored in buckets (like folders) that can be organized using labeled prefixes. The objects can be images, songs, videos, logs, or other data files.

S3 data objects can be stored using different S3 storage classes:

• S3 Standard Storage: This stores the data for frequent access with a minimum of three replicas across different zones.
• S3 Infrequent Access (IA) offers lower-latency access than the standard S3 storage class. The differences between S3-IA and standard classes are that S3-IA is cheaper, charges for data retrieval per GB, and minimal object storage size is 128 kb, which makes it suitable for backups.
• S3 One Zone-Infrequent Access (S3 One Zone-IA) storage class doesn't replicate the data in various zones and is 20% cheaper than other storage classes. It's only suitable for regenerable or trivial data.
• S3 Intelligent-Tiering is similar to the standard storage class. It automatically moves data to a cost-effective tier but it can cause performance issues.
• S3 Glacier is a low-cost storage class for archiving and backups, though the data access time can vary from minutes to hours.
• Amazon S3 Glacier Deep Archive is cheaper than S3 Glacier, though it takes more time to access data.

S3 also offers services like web hosting, version control, events, etc.

RDS, or Relational Database Service, stores data in a structured format (tables with rows and columns). RDS can support database engines such as MySQL, MariaDB, PostgreSQL, Oracle, Microsoft SQL Server, and Amazon Aurora. The important benefit of using RDS is the automatic handling of maintenance tasks such as patching, backup, recovery, failure detection, and repair.

RDS provides multiple configuration options for:

• Data Storage: The RDS database instance can be configured to use SSD, IOPS (input/output operations per second), and magnetic storage. The selection of magnetic storage is discouraged due to its size limit (three TiB) and lack of support for auto-scaling.
• Deployment Type: RDS instances can be deployed with a failover backup instance in different zones using Multi-AZ deployment. RDS instances can have multiple replicas for faster read access using Read Replicas, and replicas can be created in the same or different availability zones (using Multi-AZ). RDS on-demand instance charges are different as per database engine and instance capability.

AWS Elastic Block Store, or EBS, provides persistent block-level data storage that stores files in multiple volumes called blocks, which act as separate hard drives. Often an app is hosted using an EC2 (virtual machine) instance with required tools and services. EBS storage volumes can be attached with EC2 instances to store files, set up software or services, etc. EBS also supports different volume types for different hardware storage types based on performance, cost, and capacity.

AWS offers different types of NoSQL databases for different requirements:

• DynamoDB stores data as key-value pairs and offers high performance for read/write operations within single-digit millisecond duration. It's highly partitionable and allows horizontal scaling. SimpleDB is another No-SQL service, but AWS has moved to DynamoDB and stopped the development of SimpleDB.

• DocumentDB is a document-based storage database that mimics the features of MongoDB to store JSON data/objects as documents.

• Neptune is a graph-based database to store information about relations and hierarchies, or data flow direction for games, AI, drug discoveries, and network security apps.

• ElastiCache is an in-memory database (it stores data in RAM rather than disk) for instant data access for messages, events, and real-time storage.

• ElasticSearch is an analytics tool to process data such as logs or events for monitoring and performance analysis.

• QLDB, or Amazon Quantum Ledger Database, stores immutable records with cryptographically verifiable hash values, i.e. digest or secure summary. It is quite suitable for blockchain technology-based apps to store the data history using audit tables with cryptic hash values.

• AWS Redshift is a data warehouse service in the cloud that can store a huge amount of data for analysis. Redshift gives access to structured data using SQL tools. It divides the query into small parts and assigns them among the multiple nodes for parallel operations.

• AWS Data Migration Service (DMS) and Schema Conversion Tool (SCT) for importing and exporting data.

• CloudFormation service to construct a fully operational deployment environment using text or scripts (Python, Java, C#, TypeScript), with all the required resources and services to run the app.

There are other useful services that can be combined with database services to support different use cases, such as:

• Services like Athena and Lambda for data analysis with SQL or big data with AWS Lake.
• AWS Glue to extract, transform, and load data from various resources.
• Kinesis for real-time data (streams) processing. It consumes data as it arrives and processes it simultaneously to respond instantly.
• Timestream to store time-series data effectively so that the data can be available instantly for processing over any defined time interval.
• CloudWatch to implement triggers that can be used to notify the team about specific events such as offline network, crashes, exhausting resources for monitoring, and troubleshooting.
• VPC to create a virtual private cloud for logically isolated networks of resources with customized IP addresses, subnets, route tables, and gateway.
• Identity and Access Management (IAM) service to manage the privileges to access AWS resources for users and groups. Amazon provides a one-year free subscription plan for practice and learning, though it requires credit or debit card details to confirm the identity. Students and educators can also take advantage of the AWS Educate program.

Like other AWS certifications, there are no prerequisites for AWS Certified Database Specialty certification. Achieving an AWS Practitioner or Associate certification can help to build a strong foundation towards achieving AWS specialty or professional certifications.

The AWS Certified Database - Specialty exam will evaluate database and AWS skills based on different criteria: security, cost, performance, etc. Questions require an understanding of inter-service compatibility with the available configuration settings to achieve the best solution from the given options. The recommended experience for this certification consists of:

• Two or more years of experience with AWS with a good understanding of the AWS ecosystem.
• Five or more years of experience with database and analytics tools.

The exam will cover various data-oriented domains and skills:

• Deep understanding of different database services and configurations
• Implement automated solutions for deployment, scaling, troubleshooting, and monitoring
• Compliance policy assurance for AWS services as per industry standards
• Cost and performance effective solutions as per requirements and use case
• Migration support to move an app or local data to the cloud
• Ability to find the best combination of services for data storage and processing.
• Best practices to support low-maintenance, fault tolerance, caching, encryption, security, and access control.

Exam details play a significant role in effective preparation. The crucial attributes of the exam are:

The exam is comprised of multiple-choice questions, and answers can have multiple correct choices. Marks are only given if only the correct choices are selected.

The criteria for passing scores is set by using statistical analysis (scaled scoring models) and is subject to change. Points are not given for incorrect answers.

The exam can be taken online (proctored exam) or given at a physical test center provided by PSI or Pearson VUE. The benefit of opting for a physical test center is the opportunity to meet other developers and make new connections.

For an online proctored exam, applicants must be able to speak English to communicate with a proctor, who will monitor the testing environment. Online proctoring exams are not available for candidates in mainland China, Japan, Slovenia, or South Korea. More details are available here. Find the additional information about system requirements and policies here.

Due to COVID-19, test delivery providers have released strict guidelines for safety measures. Follow PSI guidelines here and Pearson VUE guidelines here for testing center availability and safety measures.

The duration of the exam is 180 minutes, though it could vary in the future depending on the content.

There is a one-time fee of $300 for a AWS Certified Database - Specialty exam and the practice exam fee is $40.

Amazon has a beta program for certification with changes to the exam’s outline or new certifications. Early access is available to a limited number of candidates (on a first come, first served basis) who can take the beta exam as well as the stable exam once it’s out of beta). This allows applicants to take the exam twice without any additional fee. The beta program also provides the benefit of 50% off of the standard exam pricing.

The exam can be rescheduled up to 24 hours before the scheduled exam time; otherwise there will be no refund and the next exam can be scheduled only after 24 hours. In case of unsuccessful attempts, the next exam can be scheduled after 14 days with the same fee, though you can use vouchers to retake the exam.

The AWS Certified Database - Specialty certification is valid for three years. The certificates will be available within five working days after a positive exam result.

Details about content and pricing vary, so make sure to verify it here.

The AWS Certified Database - Specialty certification qualifies you for various positions such as database, migration, and administrator roles, and can be applicable for associate architect roles.

• According to payscale.com and LinkedIn, the average pay of a Senior Database Administrator is US$110,000.

• There are more than 7000 jobs posted on LinkedIn and more than 2000 jobs on indeed.com as of June 2020.

Also, make sure to check Database Consultant jobs on Amazon.

Pluralsight offers quality resources to prepare for the AWS Certified Database - Specialty certification. The curated learning paths are:

• AWS Databases
• AWS Storage

The RoleIQ for Database Administrator on AWS can help you to measure your skills.

Below is a list of helpful resources such as AWS Whitepapers and study material for best practices and insights.

• AWS Database Offerings
• Planning and Designing Databases on AWS
• Exam Readiness: AWS Certified Database - Specialty

• AWS Database Whitepapers

• Aurora
• DynamoDB
• DocumentDB (with MongoDB compatibility)
• QLDB
• ElastiCache
• Neptune
• RDS
• Redshift
• Database Migration Service

• The primary focus of the AWS Certified Database - Specialty certification is on the overall implementation of database setup, so it's strongly recommended to practice and study different case studies.
• Closely study the whitepapers, they are quite important.
• Make specific and structured notes for last-minute review.

This guide explained the necessary details to get started with the AWS Certified Database - Specialty certification. Good luck with your certification.