What is a relational database?
A database made up of tables, uses keys to relate certain tables to other tables
What is each entry in a relational database called
a row
What is Amazon Auraura
A relational database engine designed to be compatible with mySQL.
How many AZs does Auraura place your dbs in
3
What happens if a database in Aurara fails
its automatically replaced.
What is Aurara managed by?
RDS
Are you billed for creating Aurora snapshots?
yes
Are you billed for sharing Aurora snapshots?
no
Is there a limit to the number of Aurora replicas you can have?
yes 15
What configuration can you launch Aurora in to be secure?
VPC - and only VPC
What is RDS
managed service for setting up, operating, and scaling a relational database in the cloud
How do you back up databases and keep software up to date on your data base with RDS
this is done automatilally with RDS
Can you deploy a database across multiple AZs with RDS?
yes, it’s an option you can select
[RDS] what is a database instance?
a db environment in the cloud with the compte and storage resources you specify.
what is the API and cli command for tetrieving db instance descriptions?
DescribeDBInstances (API)
describe-db-instances (cli)
How do you partition and re-partition data on Dynamo as your datastore grows?
You dont, it’s done automatically
What is the I/O performance and latency of DynamoDB?. what helps achieve this
high I/O, low latency. SSDs help achieve this
Is dynamo a good choice for petabytes of data with moderate reads and frequent writes?
not the best. Stoarge cost per GB is high.
is dynamo a good choice for gigabytes of data and very frequent reads and writes?
yes
What is the difference between DynamoDB and SimpleDB?
SimpleDB has a storage limit, limited request capacity it can achieve, and unmanaged partitioning and respartitioning of data to addiditonal SimpleDB servers. Dynamo is all managed and auto scaling
What is the size limit on a dynamoDB item?
400KB
what is the consistency of dynamoDB Scans?
Eventual consistency, however, you can modify scans to be consistent reads using the optional ConsistendRead parameter
What is a collection in dynamodb
a table
what is a document in dynamodb
a row
what is a key/value pair in dynamodb
a field
What is Data Wharehousing
used for bisiness intelligence. Fro pulling in very large complex data sets. It allows you to run OLAP queries by essentially copying production data into an archive.
What is ElasticCache
a web service that makes it easy to deploy, operate, and scale an in-memory cache in the claud.
It can cache the most frequently access queries, and takes that load off of your db
What is DMS
Database Migration Service. Allows you to migrate your prod database to AWS. Can do datatype transformation, compression, and parallel transfer.
What is the DMS schema conversion tool
allows you to convert one type of data to another. Such as oracle database and convert to free mysql database
What are the 2 types of backups for AWS RDS
Automated Backups and Database snapshot
whats an Automatied Backup
Allow you to recover your database to any point in time within a “retention period” (1-35 days)
What impacts happen on the database when an automate backup is being taken
storage io may be suspended and elevated latency might occur.
Whats a DB Snapshot
Done manually and stored even after RDS instance deleted.
What can help Disastar Recovery in RDS
Multi-AZ
can you use multi-AZs for performance increase?
No, it’s for Disaster Recovery only
How is a read replica different from multi-az
read replica copies your db for additional reads from instances, can boost performance. multi-az only does failover to the copied az and is for disaster recovery.
Do read replica share dns point with its parent db?
no
Does RDS need to scale manually
yes
Whats the best db pick for autoscaling of db?
DynamoDB
What are the two types of DynamoDB read consistency
Eventual consistency (defalut) less than a sec for all writes to return updated doc. Strong consistency - returns a result that reflects all writes that received a successful response prior to the read
how many units is dynamo write through put charged
10
read throughput charged every how many units?
50
What is dynamo pricing
read/write throughput plus amount of data
dynamo - how many reads per what unit can a write or read capacity unit handle
one read/write per second.
Is dynamo more expensive for reads, writes, or storage,
expensive for writes, cheap for the other p much
What is Redshift
fast and powerful fully managed, petabyte-scale data data-warehouse service
What types of nodes are on Redshift
Leader Node - manages client and connections and receives queries, and compute notes, that performs queries and computation.
How is redshift storing data and what is the advantage of that
stores in columns and sequentially. It requires less io, and supports advanced compression.
is redshift multi-az?
no, 1 az only
What is Elasticache
makes it easy to deploy operate and scale an in-memory cache in the cloud. Most frequent information asked for can be cached in the front end.
What is Memcached
a widely adopted memory abject caching system
What is Redis
popular open source key-value store that supports data structures such as stored sets and lists
If a database is too read heavy, whats a good service to aleviate that?
Elasticache
If theres lots of managment OLAP transactions, or other heavy batch read/writes adding stress to a db, what is a good service to alleviate that?
Redshift
