Database Services Flashcards
What are non-relational databases good for?
Applications that need to perform just a few well-defined queries and highly transactional applications
What are relational databases good for?
Performing complex analytics and generating reports against large data sets and ideal for reporting and analysis
What is Amazon Aurora?
It’s a relational proprietary database designed for RDS.
What is the only database type that can be used with BYOL (“bring your own license”)?
Oracle
What are the three instance classes you can choose from when deploying and RDS database?
Standard (2–96 vCPU, 8–384 GB memory)
- most applications will be good with standard
Memory optimized (4–128 vCPU, 122–3,904 GB memory) - most demanding applications
Burst-able performance (2–8 vCPU, 1–32 GB memory)
- minimal performance requirements and best for test/dev applications
What are the three types of storage offered by RDS?
General purpose SSD
- good enough for most databases
- you can allocate between 20 GB and 32 TB
- IOPS is determined by amount of storage
- bursting
Provisioned IOPS SSD
- you can specify the IOPS
- up to 32TB
- no bursting
Magnetic
- only up to 4TB and 1000 IOPS
- does not use EBS
- used for legacy systems only
What does scaling vertically mean?
It means choosing a more (or less) powerful instance type or selecting a different IOPS.
What are read-replicas?
Think “horizontal scaling.”
Basically, you can add more RDS instances that can perform read actions only.
How long will RDS keep automatic snapshots?
The default is 7 days, but you can customize that time to be anywhere from 1 to 35 days
What would be a good strategy if your Recovery Point Objective (RPO) was 5min or less?
Use multi-AZ and probably also snapshots
What are the three attribute types for DynamoDB?
Scalar
Set
Document (good for storing things like JSON objects)
How can DynamoDB use horizontal scaling to ensure consistent performance?
You can either manually or enable Autoscaling to adjust the RCU or WCU. Think “partitions” when it comes to DynamoDB and horizontal scaling.
What is RedShift?
Think “data warehouse.” RedShift can store up to 2PB!
What do you need to choose in order to spin up a new RDS?
Instance class (this defines the vCPU and memory) Database engine A type of storage (general purpose or IOPS SSD)
What two databases is Amazon Aurora compatible with?
PostgreSQL
MySQL
