Databases 101 Flashcards
What is a relational database analagous to?
A traditional spreadsheet
What does RDS stand for?
Relational Database Servers
What are the 6 flavors of relational databases engines that are compatible with Amazon?
- SQLServer
- MySQLServer
- Aurora
- Oracle
- PostgreSQL
- MariaDB
What are the 2 key features of RDS? What are they primarily for?
- Multi-AZ (for distaster recovery)
- Read Replicas (for performance)
Does RDS Multi-AZ require changing the connection string?
If you lose access to your primary database, AWS can automatically point incoming requests to your secondary database without changing the connection string
How do Read Replicas work in RDS?
- There is no automatic failover. If your primary instance goes down, you’ll need to create a new URL to connect to the secondary instance
- All writes to the primary instance are copied over to the read replica(s)
Suppose you want to be able to handle a surge of incoming traffic to your RDS instance and scale out your application. What key feature of RDS would you use to do this?
Read Replicas
What is the maximum number of read replicas that can be made from a single primary RDS instance?
up to 5 copies
What is a non-relational database best analagous to?
A JSON Object
What does OLTP stand for?
Online Transaction Processing
What does OLAP stand for?
Online Analytics Processing
What is the difference between OLTP and OLAP?
- Big difference is in the types of queries you will run
- OLTP is for a specific transaction
- OLAP will pull in a lot of data
What is Amazon’s data warehousing solution?
Redshift
What is Elasticache?
Elasticache is a web service that makes it easy to deploy, operate, and scale an in-memory cache in the cloud.
What is the benefit of using Elasticache?
- Elasticached is used to speed up performance of existing databases
- frequent identical queries
- Elasticache improves the performance of web applications by allowing you to retrieve information from fast, managed in-memory caches, instead of relyinng entirely on slower, disk-based databases.
What are the two types of open-source in-memory caching engines that Elasticache supports?
- Memcached
- Redis
Does RDS run on virtual machines?
Yes
How can you log in to the OS of an RDS instance?
You can’t
How can you patch the OS or database of an RDS instance?
This is Amazon’s responsibility (you can’t)