Databases Flashcards
What databases are available on RDS?
MySQL, SQL Server, PostgreSQL, Oracle, Aurora, MariaDB
Which database service would you choose for OLTP?
RDS
Which database service would you choose for OLAP?
Redshift
What caching services does Elasticache use?
Redis and Memcached
What can you provision for higher performance in RDS?
RDS Read Replicas to scale reads
What disaster recover solution is available for RDS?
Multi-AZ RDS deployments are perfect for DR; you can manually trigger a failover, too
What two types of backups are available for RDS?
Automatic (which are enabled by default and are stored for free in S3) and Snapshots, which are manual and incremental and ar stored even after you delete your RDS
What is the default retention period for RDS backups?
35 days
How many availability zones is DynamoDB available in by default?
3 AZs
What is the default read model for DynamoDB?
Eventual Consistent reads, which consistency is reached by 1 second
What kind of consistency can be enabled to reach consistency in less than 1 second?
Strongly consistent reads
How many tables can you have per AWS Account for DynamoDB?
256/region
What is the maximum item size in DynamoDB
400KB
What is the maximum item size in DynamoDB
400KB
What are the primary cost components of DynamoDB
Pay for reads and writes by the mullion request units and for data storage above 25GB/month
True or False: you pay for DynamoDB Data transfer to AWS services within the same region?
False
How many copies of your data does Aurora store by default?
6: 2 copies in 3 availability zones
True or False: You can share RDS Aurora snapshots across AWS accounts?
True
How many availability zones can you have with Redshift?
Only available in 1 AZ
What is the max retention for Redshift backups?
35 days
How many copies of data will Redshift attempt to maintain?
3: the original, one is S3 and the replica
What scale of data can Redshift handle?
Up to Petabytes
What advantages does Redshift have over traditional data warehouse technologies
Columnar data storage, advanced compression, no need for indices, scalability, massively parallel processing, and Redshift Spectrum for unstructured data in S3
Which service can you use to sync your on-premise database to an AWS database?
AWS Database Migration Service, which can perform homogenous and heterogenous migrations (and not just to databases, but also to S3, Elasticsearch, Kinesis, DynamoDB, DocumentDB and EC2)
