Databases Flashcards
In a relational database, what language is used to perform queries or lookups?
SQL
What type of database does NoSQL reflect?
Non relational database
In regards to database, what is meant by “schema”?
Basically, the shape of the data
What type of database offers a flexible schema?
non relational
The following are examples of what type of database?
Key-value, document, graph, in-memory, search databases
non relational
the following is an example of what type of database?
flexible (easy to evolve data model)
scalable - designed to scale out by using distributed clusters
high-performance - optimized for a specific data model
highly-functional - optimized for the data model
non relational
what does JSON stand for?
java script object notation
In the Shared Responsibility model, who is responsible for patching OS and database patching?
AWS
In the Shared Responsibility model, who is responsible for automated backup and restore, operations, and upgrades?
AWS
In the Shared Responsibility model, who is responsible for monitoring and alerts?
AWS
For RDS services, how is the storage managed?
EBS (gp2 or ioL)
Can you SSH into an RDS instance?
No
What are the two services you can utilize to create relational databases in AWS?
RDS or Aurora
This type of database is OLAP (analytics & data warehousing)
Redshift
What type of database is based on PostgreSQL but doesn’t use OLTP
Redshift
How often does Redshift load data?
every hour
Is RDS a single or multi-AZ service, and why?
multi-AZ, for data reliability (disaster recovery)
What type of replicas are provided for RDS, “read/write” or “read”?
read
what two types of query languages are supported by Amazon Aurora?
PostgreSQL and and MySQL
Aurora is ____ optimized
cloud
Aurora claims _x performance in PostgreSQL over RDS and _x performance in MySQL over RDS
3x and 5x
Aurora storage is adjusted
a. automatically
b. manually
a. automatically
Aurora storage is automatically incremented by __ GB up to a maximum of __ TB
10GB, 128TB
Which is more expensive, Aurora or Amazon RDS?
Aurora
How much more expensive is Aurora over Amazon RDS?
20%
Aurora storage (Is/Is Not) in the free tier?
Is not
Amazon RDS can have a maximum of how many “read” replicas?
5
With Amazon RDS, data is only written to where?
the main DB
Amazon RDS, how many AZs can be utilized as a fail-over?
1
Which type of managed relational database is going to be more cloud native? which one will work more with the technologies you’re probably already familiar with?
Aurora / RDS
When starting a new database from the RDS service, which database options are available to choose from?
PostgreSQL (Aurora)
PostgreSQL
MySQL (Aurora)
MySQL
MariaDB
Oracle
SQL Server
In a failover DB (multi-AZ) where is the data written to and read from?
the main DB only
The failover database is considered to be (passive/active)?
passive
When is the failover DB accessible?
only after a failure to the main DB
If you want to copy your database to another region, what is a method you can use?
Create a snapshot into another region
What would be two reasons to setup a multi-region DB deployment, where data is written to and read from one main DB but replicas are created in other regions?
one - disaster recovery if there’s an issue with a given region
less latency - the application is reading data from a “read replica” that’s in a region closer to where the application is located
Anytime you hear “in-memory databases with high performance and low latency” what should you think of?
ElastiCache
This is an example of what “helps reduce load off databases for read intensive workloads”
ElastiCache
DynamoDB replicates across how many AZs?
three
What type of database is this referring to:
“scales to massive workloads, distributed “serverless” database, millions of requests per seconds, trillions of rows, 100s of TB storage, single digit millisecond latency, low latency retrieval
Dynamo DB
If the certification exam refers to “single digit millisecond latency” and/or “low latency retrieval” - what type of database is it likely referring to?
Dynamo DB
True or False:
Dynamo DB has low cost and auto scaling capabilities?
True
What type of S3 storage class is offered by Dynamo DB?
standard and IA
the name for a fully managed, in-memory cache for DynamoDB
DynamoDB Accelerator - DAX
DynamoDB Accelerator DAX offers a __x performance improvement
10x
Theoretically, can ElastiCache be used as an in-memory DB for DynamoDB?
It could, but it’s recommended to use Dynamo Accelerator DAX instead as that is formulated for use with Dynamo
DynamoDB replication is an (active/passive) replication?
active
DynamoDB region replication is referring to as G_____ T_____.
global tables
With DynamoDB replication, read/writes are performed on which databases?
all
Redshift is used with what type of inquiry programming?
PostgreSQL
If an exam question refers to “warehouse” and “data analytics” and/or columnar data storage, you would think of this type of database.
Redshift
Redshift store data in a (columnar/row) format
columnar
Redshift payment is:
- Pay per column of data
- Reserve storage for 1 or 3 years
- Pay as you go
- paid with a valpak coupon
pay as you go
This type of database has Massively Parallel Query Execution (MPP) and is highly available
Redshift
Redshift uses a S__ interface to perform the queries
SQL
This database is integrated with BI (Business Intelligence) tools such as AWS Quicksight or Tableau
Redshift
AWS Quicksight or Tableau are considered B_______ I___________ tools
Business Intelligence
Amazon EMR stands for El___ Ma_ Red___
Elastic Map Reduce
What database is utilized in creation of Hadoop clusters (big data) to analyze and process vast amounts of data
Amazon EMR (Elastic Map Reduce)
Amazon EMR (Elastic MapReduce) is utilized to create Ha_o__ clusters
hadoop
what type of cluster is used to analyze and process vast amounts of data?
hadoop cluster
hadoop is an op__ so__ technology
open source
When using EMR, you can make a cluster of how many EC2 instances?
hundreds
EMR also supports Apa___ Sp_r_, HBase, Presto, and Flink
Apache Spark
Amazon EMR has auto_s______ and integrated with S___ instances
auto scaling, spot instances
use cases for EMR include d___ p____, m___ l____, w___ i___, big data
data processing, machine learning, web indexing, big data
From an exam perspective, anytime you see “hadoop cluster” the answer should be …
EMR
a serverless query service to perform analytics against S3 objects
Athena
what type of query language is used by Athena
SQL
The pricing for Athena is about $_ per _B of data scanned
$5 for TB of data scanned
from exam perspective, if you see “analyze data in S3 using serverless SQL” .. what type of database service should you think of?
Athena
In Athena, use com___ or col___ data for cost-savings
compressed or columnar
this service creates interactive dashboards
QuickSight
If you want to create dashboards based on your databases to help customers visualize the data, what service should be utilized?
QuickSight
D_DB is an AWS-implementation of MongoDB similar to how Aurora is an AWS implementation of PostgreSQL and MySQL
DocumentDB
M_DB is used to store, query, and index JSON data
MongoDB
MongoDB is used to store, query and index what kind of data?
JSON data
DocumentsDB is replicated across _ AZs
three
Document DB storage grows in increments of __GB up to a maximum of __TB
10 GB, 64 TB
DocumentDB can scale to m____s of workloads per second
millions
This database resonates with a planet and God of the Sea is a graph database service
Neptune
A so____ ne___ is an example of a graph dataset.
a social network
Neptune has replication across _ AZs and can have up to __ read replicas
3, 15
from an exam perspective, when you see “graph dataset” think ….
Neptune
What does Amazon QLDB stand for?
Quantum Ledger Database
Amazon QLDB is a ledger of f___ transactions
financial
Amazon QLDB has replication across _ AZs
3
This service is used to review history of all the changes made to your application data over time?
QLDB (quantum ledger database)
QLDB is a (mutable/immutable) system for which entries (can/cannot) be modified (useful for financial ledgers).
immutable / cannot
QLDB provides _x-_x better performance than common ledge blockchain frameworks
2 - 3
QLDB can manipulate data using S___
SQL
____ has a central authority component whereas Amazon M____ B____ has no decentralized component
QLDB, Amazon Managed Blockchain
Anytime you see “financial transactions” and “ledger” think….
QLDB
Managed Blockchain is considered to be (centralized/decentralized)
decentralized
_____ makes it possible to build applications where multiple parties can execute transactions without the need for a trusted, central authority
Managed Blockchain
from an exam perspective, if you see anything related to blockchains, Hyperledger Fabric or Ethereum, think …
Amazon Managed Blockchain
Managed extract, transform, and load (ETL) service
AWS Glue
what does ETL stand for (ex_, tra_, and l__d)
extract, transform, and load
How do you migrate data from one database to another?
Database migration service
When running the AWS Data Migration, the source database (is temporarily unavailable/remains available)
remains available
what is a homogeneous migration?
when the source and target DB are both the same type of DB (ie Oracle to Oracle)
what is a heterogeneous migration?
when the source and target DB are both different (ie SQL Server to Aurora)
What database?
Warehouse
OLAP (onilne analytic processing) / Redshift (SQL)
What database?
In memory
ElastiCache
What kind of database?
Key/Value database?
Dynamo and, for cache of Dynamo Accelerator DAX
What kind of database?
hadoop cluster
EMR
What kind of database?
query data on Amazon S3 (serverless & SQL)
Athena
What kind of database?
Serverless, Dashboards on your data
QuickSight
What kind of database?
“Aurora for MondoDB” (JSON - NoSQL database)
DocumentDB
What kind of database?
Financial ledger
Immutable journal
cryptographically verifiable
Amazon QLDB (Quantum Ledger database)
What kind of database?
managed Hyperledger Fabric
Etherneum
blockchains
Amazon Managed BlockChain
What kind of database?
Managed ETL (extract, transform, load)
catalog services
Glue Managed ETL
What kind of database?
migration
Data Migration Service
What kind of database?
graph
Neptune
Dynamo utilized what type of query language?
NoSQL
What is the the main purpose for RDS “read replicas”
scalability
What is the main purpose for multi-AZ deployments?
high availability
What is covered under the free tier for RDS? Dynamo?
RDS - 750 hours of usage / month
Dynamo - 25GB storage (S3 standard or IA) / usage is not free
Amazon RDS - how many instance classes are there?
three
Amazon RDS - which are actual instance classes to choose from (select three):
Standard
Memory Optimized
Compute
Database Max
Burstable performance
Standard
Memory Optimized
Burstable performance
1 - Eventually Consistent Reads
2 - Strongly Consistent Reads
A - When you read data from a DynamoDB table, the response might not reflect the results of a recently completed write operation. The response might include some stale data. If you repeat your read request after a short time, the response should return the latest data.
B - DynamoDB returns a response with the most up-to-date data, reflecting the updates from all prior write operations that were successful. However, this consistency comes with some disadvantages:
1A
2B
