Module 6: Adding a database layer

Question 1

what are considerations when adding a database layer?

Answer 1

-Scalability
-Storage requirements
-Data characteristics
-Durability

Question 2

Benefits of Relational vs benefits of non relational databases (No SQL)

Answer 2

Relational:
Ease of use, Data integrity, reduced data storage, Common language.ACID compliant

Non relationnal:
Flexible, scalable and high performance

Question 3

Use case for non relationnal database (NoSQL)

Answer 3

Fast access, and high read and write throughput. Efficient when considering a caching option to improve read performance, storing Json files or requiring millisecond retrieval.

Question 4

Use case for relational

Answer 4

The workload involves transactional processing, optimized for structured data stored in table and supports complex queries. Best low effort solution to many use cases.

Question 5

Is there only one type of NoSQL database

Answer 5

No. There is document based, graph based, key-value, in memory, search…Can be structured, semi structured or unstructured. Each object can have its own structure.

Question 6

Amazon Database options for Relational databases

Answer 6

Amazon RDS

Question 7

Amazon Database option for non relational databases

Answer 7

Dynamo DB
Neptune
Elasticache

Question 8

What does vertically scaling the databse means?

Answer 8

Expand the resources the server uses to increase capcity. (update memory, storage, computing power) Main issue: downtime.

Question 9

What does scalling horizontall means

Answer 9

Increase the number of server the database runs on. Can be done while running = No downtime.

Question 10

RDS compatibilities

Answer 10

Aurora:
1) Mysql
2) Postgresql

RDS:
1)mysql
2)mariaDB
3)postgresql
4)Oracle
5)SQL server

Question 11

What os the relation between RDS end EBS?

Answer 11

RDS uses EBS for database and log storage. Allowing you to scale the storage capacity to the database instance

Question 12

Whar can help make RDS Available and durable ?

Answer 12

Multi AZ deployment and read replicas

Question 13

How can you make RDS more secure?

Answer 13

Using VPC,
IAM;
Security groups tocontro IP,
SSL or TLS connections;
Encrypt with an AWS KMS;
Use the security feature of your DB engine

Question 14

Advantage of RDS vs on permise?

Answer 14

No need to provision and maintain

Question 15

An RDS can contain several isolated database environments with multiple user-created database . TRUE or FALSE ?

Answer 15

TRUE

Question 16

What is Aurora?

Answer 16

Aurora is RDBMS (Rleational Database Management System).
It supports Mysql and postgresql.

Question 17

Advantage of Aurora

Answer 17

Cost efficient and multi AZ deployment with Aurora Replicas

Question 18

Aurora facts:

Answer 18

Max 64TB per instance
Up to 15 low latency read replicas
Replication across 3 AZ
Continuous back up to S3
Point in time recovery

Question 19

Aurora serverless is an on demand auto scaling config for Aurora. What is it suitable for?

Answer 19

Variable workloads
New applications
Dev and testing
Capacity planning

Question 20

When setting up an RDS instance you can select the EC2 type and sizing it will run on ?

Answer 20

Yes:

General purpose (T AND M) or Memory optimized (R AND X)

Question 21

What is RDS proxy used for ?

Answer 21

It is located between the database and the application. The proxy receives the request and pools them before sending it to the database. Like that less requests are using the ressources of the database. If hte database fails, the proxy queue the requests and redirect the request to an other Db instance.

Question 22

What does Dynamo DB supports?

Answer 22

No Sql database, supporting key-value and document t^data models

Question 23

What is the advantage of Dynamo DB?

Answer 23

High read write throughput. Automatically scales. Millisecond performance

Question 24

What is Dynamo DB used for

Answer 24

Developing applications, mission critical worloads with priority on speed scalability and data durability

Question 25

Composition of dynamo DB

Answer 25

Table => items => attributes.

Attributes have a partition key,sort key and attribute list

Question 26

Not understood:
GSI and LSI

Answer 26

Globa secondary indexes and Local Secondary indexes. I understood it allows to reshape the tables for varying queries.
It creates copies of the table. Diff between LSI and GSI is that LSI will be consistent, while GSi may not (will eventually be but requires a bit of time if operation are in process): With LSI Same partition key but different sort key

Question 27

What do I use to replicate Dynamo DB accross several regions ?

Answer 27

Dynamo DB global tables

Question 28

Dynamo DB security best practuce

Answer 28

Use IAN
Use VPC
Use cloudtrail to monitor KMS usage
and operations
monitor config using AWS config
Check compliance with AWS Config Rules

Question 29

What db option is used for analytics workloads.?

Answer 29

Redshift

Question 30

What db option is used for document database

Answer 30

Amazon DocumentDB (Mongo compatible) JSON like

Question 31

What db option is used for Apache Cassandra?

Answer 31

Amazon Keyspaces
(Typical example trade monitoring)

Question 32

What db option is used for in memory workloads?

Answer 32

Amazon MemoryDB
Used for Caching, bank user transaction…

Question 33

What DB service is used for Graph database?

Answer 33

Amazon Neptune

Question 34

What DB option is used for Timeseries

Answer 34

Amazon Timestream

Question 35

What db option is used for Ledger database

Answer 35

Amazon Quantum Ledger Database (QLDB)
Immutable and verifiable history, with cryptographie in transaction log.
For storing financial transaction or maintaining claim history.

Question 36

Consideation for choosing the right DB?

Answer 36

Suitable workload
Data nodel
Features and benefits
Common use cases

Question 37

Migrating data to AWS databases. What is the service used

Answer 37

Amazon DMS (Data Migration services)

Question 38

For heterogeneous database migration

Answer 38

DMS Fleet advisor
Automatically inventories and acces on permise data. It s a discovery tool.
Then there is a shema conversion tool to adjust an sql schema to an equivalent sql target.