AWS Certified Database - Specialty (RDS) Flashcards
Key focus areas
RDS 25% Aurora 25% DynamoDB 20% Database Migration 20% Automation 5% Others 5%
What are the 3 AWS services that support relational databases?
Aurora, RDS and Redshift
What are the 2 AWS services/features that support key-value databases?
DynamoDB and DAX
What is the AWS service that supports document databases?
DocumentDB
What is the AWS service that supports in-memory databases?
ElastiCache which has 2 flavours: ElastiCache for Redis and ElastiCache for Memcached
ACID database
ACID (atomicity, consistency, isolation, durability) is a set of properties of database transactions intended to guarantee data validity despite errors, power failures, and other mishaps.
most typically relational databases
Does DynamoDB enforce ACID transactions?
No
4 examples of non-relational databases
DynamoDB, DocumentDB, Neptune and ElastiCache
BASE compliant databases
Basically Available Soft-state Eventually consistent
non-relational databases
ACID vs BASE
strong consistency vs high performance
Which 6 SQL engines does Amazon RDS support?
PostgreSQL, MySQL, MariaDB, Oracle, Microsoft SQL Server and Aurora
Is Amazon RDS a managed service?
Yes When you use RDS, AWS managed everything: - AWS manages hardware - AWS manages software (OS) - AWS manages application (database)
Does Amazon RDS support autoscaling?
Yes
What does Amazon RDS use for storage?
EBS
How does Amazon RDS provide high availability?
Amazon RDS provides high availability and failover support for DB instances using Multi-AZ deployments.
When you provision a Multi-AZ DB instance, Amazon RDS automatically creates a primary DB instance and synchronously replicates the data to a standby instance in a different Availability Zone (AZ). In case of an infrastructure failure, Amazon RDS performs an automatic failover to the standby DB instance.
What are the benefits of using RDS in comparison to database in EC2 instance?
- automated provisioning, OS patching
- continuous backups and restore to specific timestamp
- monitoring dashboards
- read replicas
- multi a-z deployments
- maintenance windows for upgrades
- supports vertical and horizontal scaling
BUT you can’t ssh into database instances
What instance types does RDS offer?
on demand (pay per hour) and reserved (discounts for 1-year or 3-year contract) instances
What are the characteristics of database instance classes of RDS?
memory, CPU and I/O capacity
What are the available RDS instance classes?
standard, memory-optimized and burstable performance
RDS: How do CPU credits work? What type of database instance are they related to?
burstable performance
Which are the Amazon RDS storage types?
General Purpose SSD
Provisioned IOPS
Magnetic
How is storage autoscaling enabled in RDS?
(go to that checkbox)
How much downtime is there during RDS autoscaling?
None
Can the default parameter group of RDS be edited?
No