Categories
AWS Certification

The unofficial guide to AWS Certified Database Specialty Exam

Here is unofficial guide on how to prepare to AWS Certified Database Specialty exam that I have passed in the beta version recently (03.2020).

Image of my AWS CDBS Certificate

As I recently got the information that I have passed the beta version of the brand-new AWS Certified Database – Specialty exam, I would like to share my thoughts and preparation process for it.

Below, you will find a summary of my experience and an extensive list of materials that I have used.

Beta Certification Process

First things first, I want to share my feelings about beta certification as it was the first time for me.

There are not so many differences when it comes to scheduling and exam itself. However, the major one is the price, as you can take it for 50% of a regular rate. The new thing is that are time and quantity limitations when it comes to available seats – in my case, they have announced like 200 people and 2-3 months over which you can schedule an exam.

Regarding the exam itself, you have a little bit more time than usual – and a bit more questions than usual. Also, right after the official part of the exam, there is a survey about the questions, but I think it is standard practice for all exams nowadays.

One significant difference is the scoring process, which could take up to 90 days, so you do not have any information about the result right after. You have no clue, no Congratulations, nor anything else. I think it is required due to calibration and the thresholds and unified evaluation scoring.

Blueprint and Prerequisites

I want to start with reference to the official blueprint:

Scoring percentages from the official exam blueprint.

The exam is Amazon RDSAurora, and AWS DMS heavy. I would not approach this exam without extensive experience in Amazon RDS and AWS Database Migration Service. The rest of the services are rather covered on an elementary level – depending on your experience that is good or bad. 😉

Additionally, it is a Specialty exam, so it requires a good knowledge of AWS on the level of Associate certificates, and they require that during an exam.

One thing you have to be aware of – as it is a new certificate, there are no online courses, nor question sets available (at least that is the state in March 2020). So you need to rely on your own experience and deliberate practice, plus such blog posts as this one spread over the interwebz. 😉

My thoughts about the exam content

Personally, I expected broader coverage for all database services available in the portfolio, when, in fact, I had most of my questions related to Amazon RDS and AWS DMS (not even DynamoDB).

I understand that many services are new (and some are covered by the other exams – e.g., Redshift). Yet still, it was disappointing – having only around 10 questions about DynamoDB and 2 about Elasticache, and maximally 1 question for other services is quite sad, especially taking into consideration that AWS has such a diversified portfolio in this space.

Here is the list of topics covered on my exam that I remember (bear in mind that I did it more than 3 months ago, YMMV):

  • Amazon RDSmajority (~40%):
    • You have to know inside-out read replicas and multi-AZ deployments.
    • Maintenance and backups.
    • Exporting, analyzing, and manipulating logs.
    • Performance Insights and CloudWatch metrics.
    • Performance and security tuning based on parameter and option groups (especially about SSL).
    • Pricing and Reserved Instances.
    • IAM authentication.
    • Event Subscriptions.
    • Surprise: no question about details of any DB engine, neither the open-source or commercial. Heavy knowledge or experience about one particular database does not help at all.
  • Amazon Auroraa lot (~15%):
    • Scaling reads and writes.
    • Amazon Aurora Global Database.
    • Separation storage from compute.
  • AWS Database Migration Servicea lot (~15%):
    • AWS Schema Conversion Tool.
    • Use cases for AWS DMS and AWS SCT.
    • Combining AWS DMS with AWS Snowball for large migrations.
    • Migrating from Amazon RDS to Amazon Aurora.
    • Surprise: literally no question about migrating from SQL Server or Oracle.
  • Amazon DynamoDBnot so much as I expected (~10%):
    • Various modes (on-demand, provisioned throughput), which includes pricing.
    • Use cases for GSI and LSI.
    • Difference between strongly consistent reads/writes and eventually consistent reads/writes.
    • Amazon DynamoDB Streams and Global Tables.
    • Surprise: just one question about table design.
  • AWS CloudFormation (~5%):
    • Managing stateful resources, which includes Stack and Deletion Policies.
    • Managing sensitive information using AWS Secret Manager and AWS SSM Parameter Store.
  • AWS Key Management Service (~5%):
    • Enabling encryption for Amazon RDS and Amazon Aurora with minimal downtime.
    • Manipulating the encrypted database snapshots and copying them across regions.
  • Troubleshooting Database Connection Issues (~5%):
    • Those pesky Security Groups and NACLs.
    • Connecting to Amazon RDS with SSL.
  • Other (~5%):
    • One question about Amazon Neptune.
    • One question about Amazon DocumentDB.
    • Two questions about Amazon Elasticache (and two about Redis, IIRC both about clustering and scaling).
    • One or two general and high-level questions about Amazon Redshift.
    • Lengthy questions about choosing proper database for a given use case.

Resources

As I stated above, there are no online courses or sets of questions dedicated to that particular exam. However, there are some interesting online courses in Linux Academy and A Cloud Guru worth checking:

Also Qwiklabs and Linux Academy Hands-on Labs for Amazon RDS, Aurora and DMS are very helpful, but you can do similar stuff on your own, I have prepared a list for you (those are examples, you do not have to follow and do all of those):

  • Amazon RDS:
    • Exercise: Parameter Groups, Option Groups, Logs.
    • Exercise: Maintenance Windows.
    • Exercise: Read Replicas.
    • Exercise: Multi-AZ.
    • Exercise: RDS with Serverless.
    • Exercise: Backup, Snapshots, Restore.
    • Exercise: Publicly available database.
    • Exercise: Sizing the database (PostgreSQL).
    • Exercise: Sizing the database (Oracle).
    • Exercise: Sizing the database (MySQL).
    • Exercise: Encryption.
    • Exercise: Connect IAM with RDS for account management.
    • Exercise: Amazon RDS Logs to Amazon S3.
  • AWS Database Migration Service:
    • Exercise: Migrating DB from EC2 MySQL to Aurora.
    • Exercise: AWS Schema Conversion Tool.
  • AWS Key Management Service:
    • Exercise: Encrypting data inside database with use of AWS SDK client and AWS KMS.
  • Amazon Secrets Manager:
    • Exercise: Setting up passwordless credential setup with use of Amazon Secrets Manager and CloudFormation.
    • Exercise: Password rotation with use of Amazon Secrets Manager.
  • Amazon Aurora:
    • Exercise: Read Replicas.
    • Exercise: Multi-AZ.
    • Exercise: Backup, Snapshots, Restore.
    • Exercise: Aurora PostgreSQL.
    • Exercise: Aurora MySQL.
    • Exercise: Aurora Serverless.
    • Exercise: Sizing the database.
    • Exercise: Encryption.
  • Amazon Neptune:
    • Exercise: Importing datasets to Neptune cluster.
    • Exercise: Connecting to the cluster.
    • Exercise: Querying with Gremlin.
    • Exercise: Querying with SPARQL.
    • Exercise: Read Replicas.
    • Exercise: Backup and Restore.
    • Exercise: Sizing the database.
  • Amazon Elasticache:
    • Exercise: Sizing the database.
    • Exercise: Using Redis as cache.
    • Exercise: Using Memcached as cache.
    • Exercise: Replication and encryption options for both engines.
  • Amazon Elasticsearch Service:
    • Exercise: Sizing the database.
    • Exercise: Connecting and querying.
    • Exercise: Streaming CloudWatch Logs to Elasticsearch.
    • Exercise: Public and private access (VPC endpoint).
    • Exercise: ELK stack.
    • Exercise: Searching and advanced queries.
    • Exercise: Indexes.
  • Amazon DynamoDB:
    • Exercise: Designing the NoSQL schema.
    • Exercise: Partition Key and Sort Key.
    • Exercise: Index Overloading.
    • Exercise: LSI.
    • Exercise: GSI.
    • Exercise: Transactions.
    • Exercise: Global Tables.
    • Exercise: Provisioned Throughput vs. On Demand.
    • Exercise: Capacity Planning.
    • Exercise: Backup, PITR and restore.
    • Exercise: Hot Partitions – Write.
    • Exercise: Hot Partitions – Read (DAX).
    • Exercise: DynamoDB Streams.
  • Amazon DocumentDB:
    • Exercise: Migrate from MongoDB with use of AWS DMS.
    • Exercise: Designing the NoSQL document-like schema.
    • Exercise: Read Replicas.
    • Exercise: High Availability and Redundancy.
  • Amazon Redshift:
    • Exercise: Sizing the data warehouse.
    • Exercise: Connecting.
    • Exercise: Querying.
    • Exercise: Designing the schema.
    • Exercise: Users Management.
  • Databases on Amazon EC2:
    • Exercise: Run MySQL on EC2.
  • AWS Systems Manager:
    • Exercise: Rebooting all RDS instances with AWS SSM Automation Workflow.

List of AWS whitepapers worth reading

Regarding whitepapers for this exam, I have one remark: focus more on re:Invent videos (especially deep dives into RDS, Aurora, DynamoDB, AWS DMS, and Performance Insights).

Nevertheless, there are some papers worth reading. Here is the list that I have read and my recommendations on how important each one is:

Design and Architecture

Amazon RDS and Aurora

AWS Database Migration Service

Amazon DynamoDB

Other Services

List of re:Invent videos worth watching

Here is my playlist that I watched and think those are valuable:

I know it may look like much watch time, but watching those on 1.5x speed is still pleasant. And I cannot stress that enough: those are more important than whitepapers. I experienced many more questions than I recalled from the re:Invent talks.

Now it’s your turn!

From now on, exam registration is open for everybody, so why not try to get another one to your collection? 😉 I hope that my article helped to prepare and evaluate your knowledge. Good luck on your exam! 💪

By Wojciech Gawroński

Principal Cloud Architect at Pattern Match. Infrastructure as Code, DevOps culture and AWS aficionado. Functional Programming wrangler (Erlang/Elixir).

Comments

This site uses Akismet to reduce spam. Learn how your comment data is processed.