Databases Flashcards
Is S3 a database?
Yes. For big objects, backups, archives.
What are Joins in databases and what kind of database is good for this feature?
A JOIN is a SQL instruction. used to query combined data from different tables by using values common to both tables.
If you need to use joins, you need a relational database.
What are good databases for performing JOINS or online transactions?
SQL DBs: RDS, Aurora.
What kind of database you need if you need a more flexible option to store data?
A no SQL database like DynamoDB.
What are good options of databases for caching?
DAX to use with DynamoDB.
Elasticache for caching other databases, like RDS, etc.
What are great databases for data warehouses?
Redshift, Athena, EMR.
What database is great when database usage has sudden big spikes?
DynamoDB
What database is great when you have rapidly evolving schemas?
DynamoDB
What is a great database that can work as a serverless cache?
DynamoDB
What is a great database for very big objects?
S3.
How does AWS implement mongodb?
With DocumentDB
What kind of db is mongodb?
noSQL.
AWS Managed similar to aurora. It doesn’t have a serverless option.
What is a great database to store, query and index json data?
MongoDB
How does documentdb work?
Very similar to aurora, but for mongodb.
Managed db.
HA across 3 AZ.
Auto scaling storage and throughput.
What is a great database for graphs or charts?
Neptune.
Great for creating databases for interconnected data. Like for example a use case would be a social network.
What are neptune streams?
A history of all changes made to your neptune graph, in order.
Useful to send notifications.
Stream data is accessible through rest api.
Which AWS Services uses Apache Cassandra?
Amazon Keyspaces
What is a great database for a ledger?
Amazon QLDB (Quantum ledger Database).
What are the general characteristics of QLDB?
Its immutable.
For Ledgers.
Fully managed.
Serverless.
HA 3 AZ.
Use cases pf QLDB?
To review the history of all changes made to your application data.
What is a great service for storing time series data?
Amazon Timestream.
Time series is data that has a year related to it.
What is the main advantage of using timestream instead of a relational database?
1000s times faster and 1/10th the cost of a relational database.
Handles time-stamped data better.
Which database is redis compatible?
Elasticache
You want to migrate an on-premises MongoDB NoSQL database to AWS. You don’t want to manage any database servers, so you want to use a managed NoSQL Serverless database, that provides you with high availability, durability, and reliability, and the capability to take your database global. Which database should you choose?
Amazon RDS
Amazon DynamoDB
Amazon DocumentDB
Amazon Aurora
Amazon DynamoDB
DocumentDB is not serverless.
What is the best database for Online Transaction Processing (OLTP)?
Postgre. For aws its RDS or Aurora.
