Chapter 5: Database Flashcards
What are the 6 different rational database’s that AWS supports?
1) Microsft SQL Server
2) Oracle
3) MySQL Server
4) PostgreSQL
5) Amazon Aurora
6) MariaDB
Reference:
https://learn.acloud.guru/course/aws-certified-solutions-architect-associate/learn/dbs-on-aws/db-101/watch
What does RDS stand for?
Relational Database Service
What are 2 key features of RDS?
1) Multi-AZ - For Disaster Recovery
2) Read Replica - For Performance
Reference:
https://learn.acloud.guru/course/aws-certified-solutions-architect-associate/learn/dbs-on-aws/db-101/watch
Example formate of Database Connection String.
myexampledb.a1b2c3d4wxyz.us-west-2.rds.amazonaws.com
Reference:
https://learn.acloud.guru/course/aws-certified-solutions-architect-associate/learn/dbs-on-aws/db-101/watch
What happens in the even if the primary database in an AZ zone goes down? Specific with to Multi-AZ
Every-time you do write to a database it copies it to the secondary database synchronously.
The DNS record (the connection string) would point to the secondary Database stored in another AZ zone.
Fail is automatic with Multi-AZ. Using same DNS link.
Reference:
https://learn.acloud.guru/course/aws-certified-solutions-architect-associate/learn/dbs-on-aws/db-101/watch
What happens in the even if the primary database in an AZ zone goes down? Specific to Read Replica.
If you lose the primary database, there’s no automatic fail over. You need to create a new URL and point it to the Read Replica Database. The Read Replica will have all the existing data from the primary since it copies everything from primary while it was active.
Reference:
https://learn.acloud.guru/course/aws-certified-solutions-architect-associate/learn/dbs-on-aws/db-101/watch
What are Non-relational Database?
Collection = Table
Document = Row
Key Value Pairs = Fields / Columns
Might be in JSON format
Reference:
https://learn.acloud.guru/course/aws-certified-solutions-architect-associate/learn/dbs-on-aws/db-101/watch
What is Data Warehousing?
Used for business Intelligence.
Used to pull in very large and complex data sets. Usually uses by management to do queries on data.
Reference:
https://learn.acloud.guru/course/aws-certified-solutions-architect-associate/learn/dbs-on-aws/db-101/watch
What is OLTP?
Online Transaction Processing
Eg. Order Number 1234567890
Run query that pulls up the row of data such as name, date, address to deliver to, delivery status, etc.
RDS is used for OLTP
Reference:
https://learn.acloud.guru/course/aws-certified-solutions-architect-associate/learn/dbs-on-aws/db-101/watch
What is OLAP?
Online Analytics Processing
Eg. Net Profit for EMEA and Pacific for the Digital Radio Product. So pull in large numbers of records. Sum of the radios sold in EMEA. Sum of Radios in Pacific. Unit Cost of Radio in each region, etc. Sale price of each radio, unit cost.
Redshift is used for OLAP.
Reference:
https://learn.acloud.guru/course/aws-certified-solutions-architect-associate/learn/dbs-on-aws/db-101/watch
What is Amazon’s Data Warehouse Solution?
Redshift
It addresses the need of:
Data Warehousing Database uses different type of architecture both from database perspective and infrastructure layer
Reference:
https://learn.acloud.guru/course/aws-certified-solutions-architect-associate/learn/dbs-on-aws/db-101/watch
What is ElastiCache?
It is a web service that makes it easy to deploy, operate and scale an in-memory cache in the cloud.
Way of caching most common web queries. Speed of performance of existing databases.
Reference:
https://learn.acloud.guru/course/aws-certified-solutions-architect-associate/learn/dbs-on-aws/db-101/watch
What are 2 open source in-memory caching engines?
1) Memcached
2) Redis
Reference:
https://learn.acloud.guru/course/aws-certified-solutions-architect-associate/learn/dbs-on-aws/db-101/watch
What is DynamoDB?
NoSQL Database
Reference:
https://learn.acloud.guru/course/aws-certified-solutions-architect-associate/learn/dbs-on-aws/db-101/watch
Summary of Relational Database
- RDS Runs on virtual machine
- you cannot log into these operating systems
- Patching of RDS Operating system and DB is Amazon’s responsibility
- RDS is NOT serverless (with the exception of Aurora, it is server-less)
Reference:
https://learn.acloud.guru/course/aws-certified-solutions-architect-associate/learn/dbs-on-aws/create-rds/watch
What are the 2 different types of Backups for RDS?
1) Automates Backups
2) Database Snapshots
Reference:
https://learn.acloud.guru/course/aws-certified-solutions-architect-associate/learn/dbs-on-aws/backup-multi-az/watch
How do Automates Backups work?
- Allow you to recover info within the retention period
- Retention period is between 1 - 35 days
- Backups date a full daily snapshot and will also store transaction logs throughout the day
- when recovering, aws first chooses the most recent daily back up and apply the transaction logs relevant to the day
- enabled b default
- backups stored in S3 and storage space = size of db
Reference:
https://learn.acloud.guru/course/aws-certified-solutions-architect-associate/learn/dbs-on-aws/backup-multi-az/watch
How do DB Snapshots work?
- They are done manually
- they are stored after you delete the original RDS instance, unlike automated backups
Reference:
https://learn.acloud.guru/course/aws-certified-solutions-architect-associate/learn/dbs-on-aws/backup-multi-az/watch
What happens with you restore a DB (no matter which way)?
The restored version of the DB will be a new RDS instance with new DNS endpoint.
eg.
Old: original.eu-west-1.rds.amazonaws.com
New: restored.eu-west-1.rds.amazonaws.com
How does encryption at rest works with RDS?
Encryption is supposed for all the rational databases. It’s done using Amazon’s KMS. Once RDS instance is encrypted, the data stored at rest in the underlying storage is encrypted, as are the automated backups, read replicas and snapshots.
Reference:
https://learn.acloud.guru/course/aws-certified-solutions-architect-associate/learn/dbs-on-aws/backup-multi-az/watch
What are Read Replicas?
- Allows you to have read-only copy of - your production database.
- Improve performance.
- You can have up to 5.
- Read replicas of read replicas
- You can promote read replica to be it’s own database, but then it breaks replication
- Available for all RDS’
- Each replica has it’s own DNS
Reference:
https://learn.acloud.guru/course/aws-certified-solutions-architect-associate/learn/dbs-on-aws/backup-multi-az/watch
What are the basics of DynamoDB?
- Stored on SSD storage
- Spread across 3 geographically distinct data centres
- Eventual Consistent Reads (Default)
- Strongly Consistent Reads
Reference:
https://learn.acloud.guru/course/aws-certified-solutions-architect-associate/learn/dbs-on-aws/ddb/watch
What are eventual consistent reads?
Consistency across all the copies of the data is usually reached within a second.
Reference:
https://learn.acloud.guru/course/aws-certified-solutions-architect-associate/learn/dbs-on-aws/ddb/watch
What are eventual consistent reads?
Returns a result that reflects all writes that received a successfully response prior to the read.
Reference:
https://learn.acloud.guru/course/aws-certified-solutions-architect-associate/learn/dbs-on-aws/ddb/watch
What is DynamoDB Accelerator (DAX)?
- Fully managed, highly available, in-memory cache
- 10 performance improvement.
- Reduces requests time from milliseconds to microseconds - even under load
- No need for developers to manage caching logic
- Compatible with dynamoDB API calls
reference:
https://learn.acloud.guru/course/aws-certified-solutions-architect-associate/learn/dbs-on-aws/fd7aaf78-a88a-4b61-aa4c-95cf26fb16c4/watch
What is a transaction?
- multiple all-or-nothing operations
- financial transaction
- fulfilling orders
- 2 underlying reads or writes (1 to prepare, 1 to commit)
reference:
https://learn.acloud.guru/course/aws-certified-solutions-architect-associate/learn/dbs-on-aws/fd7aaf78-a88a-4b61-aa4c-95cf26fb16c4/watch
What is on-demand capacity?
- pay-per-request pricing
- balance cost and performance
- no charge for read/write - only storage and backups
- pay more per requests than with provisioned capacity
- use for new product launches
reference:
https://learn.acloud.guru/course/aws-certified-solutions-architect-associate/learn/dbs-on-aws/fd7aaf78-a88a-4b61-aa4c-95cf26fb16c4/watch
What does on-demand backup and restore allow you to do?
- full backups at any time
- zero impact on table performance or availability
- consistent within seconds and retained until deleted
- operates within same region as the source table
reference:
https://learn.acloud.guru/course/aws-certified-solutions-architect-associate/learn/dbs-on-aws/fd7aaf78-a88a-4b61-aa4c-95cf26fb16c4/watch
What are Point in time recovery (PITR)?
- protects against accidental writes or deletes
- restores to any point in the last 35 days
- incremental backups
- not enables by default
- latest restorable timestamp is 5 minutes in the past
reference:
https://learn.acloud.guru/course/aws-certified-solutions-architect-associate/learn/dbs-on-aws/fd7aaf78-a88a-4b61-aa4c-95cf26fb16c4/watch
What are Streams?
- Time-ordered sequences of item-level changes in a table
- Stored for 24hrs
- inserts, updates, deletes
- combine with lamda functions for functionality liked stored procedures
reference:
https://learn.acloud.guru/course/aws-certified-solutions-architect-associate/learn/dbs-on-aws/fd7aaf78-a88a-4b61-aa4c-95cf26fb16c4/watch
What are global tables?
- Globally distributed applications
- Based on DynamoDB streams
- Multi-region redundancy for DR or HA
- No application rewrites
- Replication latency under 1 second
What is Database Migration Service (DMS)
DMS used to facilitate migration from source database to target database.
reference:
https://learn.acloud.guru/course/aws-certified-solutions-architect-associate/learn/dbs-on-aws/fd7aaf78-a88a-4b61-aa4c-95cf26fb16c4/watch
How can you have security within DynamoDB?
- Encryption at rest using KMS
- Site-to-site VPN
- direct connect (DX)
- IAM policies and roles
- fine-grained access
- cloudwatch and cloud trail
- VPC endpoints
Reference:
https://learn.acloud.guru/course/aws-certified-solutions-architect-associate/learn/dbs-on-aws/fd7aaf78-a88a-4b61-aa4c-95cf26fb16c4/watch
What is RedShift?
Fast and powerful, fully managed, petabyte-scale data warehouse service in cloud.
Reference:
https://learn.acloud.guru/course/aws-certified-solutions-architect-associate/learn/dbs-on-aws/redshift/watch
Redshift can be configured in which 2 ways?
1) Single node
2) Multi node
- Leader node
- Compute node
Reference:
https://learn.acloud.guru/course/aws-certified-solutions-architect-associate/learn/dbs-on-aws/redshift/watch
Redshift uses Advanced Compression. What is Advance Compression?
Column data stores can be compressed much more than row-based data stores because similar data is stored sequentially on disk.
Redshift employs multi compression techniques and can often achieve significant compression relative to traditional relational data stores.
Reference: https://learn.acloud.guru/course/aws-certified-solutions-architect-associate/learn/dbs-on-aws/redshift/watch
What is Massively Parallel Processing (MPP)?
Redshift automatically distributes data and query across all nodes. Redshift makes it easy to add nodes to your data warehouse and enables you to maintain fast query performance as your data warehouse grows.
Reference: https://learn.acloud.guru/course/aws-certified-solutions-architect-associate/learn/dbs-on-aws/redshift/watch
What is apart of Redshift backups?
- enabled by default with 1 day retention period
- maximum retention period is 35 days
- redshift always attempts to maintain at least three copies of your data (the original and replica on the compute nodes and a backup in Amazon S3)
- redshift can also asynchronously replicate your snapshots to S3 in another region for disaster recovery
Reference: https://learn.acloud.guru/course/aws-certified-solutions-architect-associate/learn/dbs-on-aws/redshift/watch
