Databases Flashcards
SQL Server, Oracle, MySQL, PostgreSQL, MariaDB and Amazon Aurora are examples of what database type?
RDS (Relational Database Service)
______ databases are best for OLTP (Online Transition Processing) Workloads like processing lots of small transactions like customer orders, banking transactions, payments, and bookkeeping systems.
RDS (Relational Database Service)
True or False. RDS is most suitable for OLAP (Online Analysis Processing).
False.
______ is most suitable for OLAP tasks, like analyzing large amounts of data, reporting and sales forecasting.
Redshift
True or False. Read replicas are primarily used for scaling, and disaster recovery.
Read Replicas are not suitable for disaster recovery
________ a read-only copy of your primary database in the same availability zone, cross-AS or cross-region that is used to increase or scale read performance.
Read Replicas
______ is an exact copy of your production database in another availability zone and is only used for disaster recovery.
RDS Multi-AZ
If you can’t, for some reason, create a read replica of your primary database, what is a likely cause?
You haven’t turned on automatic backups.
Amazon’s proprietary database.
It’s compatible with MySQL as well as PostgreSQL.
Aurora
_________ provides a relatively simple, cost-effective serverless database option for infrequent, intermittent, or unpredictable workloads.
Aurora Serverless
Aurora maintains ____ copies of your data in each Availability zone, with a minimum of 3 availability zones: so _____ copies of your data.
2, 3, 6
True or false? You can share Aurora snapshots with other AWS accounts.
True
3 types of replicas available with Aurora
Aurora Replicas, MySQL Replicas, PostgreSQL replicas.
True or False. Automated failover is only available with Aurora replicas.
True
Dynamo DB is stored on what type of storage?
SSD
DynamoDB is spread across how may geographically distinct data centers?
3
___________ reads means that consistency across all copies of data within DynamoDB is usually reached within about a second, and repeating a read after a short time should return the updated data. And this gives you the best read performance.
Eventually consistent
If your application needs to automatically get
any changes to the data within DynamoDB, you want to turn on ___________ reads. This will return a result that reflects all writes that have received a successful response prior to the read.
strongly consistent
____________ provides developers
with atomicity, consistency, isolation, and durability (ACID) across one or more tables within a AWS account or AWS region.
DynamoDB transactions
If you see something about ACID requirements
with DynamoDB, you need to use DynamoDB transactions. This is basically means
you’ve got all-or-nothing transactions. So you either need to add an item to all the tables in one transaction, but if one of those tables fails for whatever reason, you don’t want one item going into one table, not into another table,
because that wouldn’t have ACID consistency.
So you need to make sure you’ve got DynamoDB transactions turned on, and that way, either the write will happen or it won’t.
True or False? DynamoDB On-Demand Backup and Restore provides full backups at any time; backups older than 360 days are deleted by default.
False. DynamoDB On-Demand Backup and Restore provides
- full backups at any time consistent within seconds and retained until deleted.
True or False. DynamoDB On-Demand Backup and Restore operates within the same region as the source table.
True
Select the features that correct describe DynamoDB Point-in-Time Recovery (PITR)
a. Protects against accident writes or deletes
b. Restore to any point in the last 60 days
c. Differential Backups
d. Not enabled by default
e. Latest restorable: 5 minutes in the past
a. Correct
b. Incorrect. Correct answer is restore to any point in the last 35 days.
c. Incorrect. Correct answer is incremental Backups
d. Correct
e. Correct
DynamoDB _______ allows you to maintain First-In-First-Out records of your data. So as you go and add transactions, basically it’s given a sequence number. These sequences are stored in a stream, and the data’s broken up into shards. So it’s just time-ordered sequences of item-level changes in a table.
DynamoDB streams.
As you go and add transactions, basically it’s given a sequence number. These sequences are stored in a stream, and the data’s broken up into shards. So it’s just time-ordered sequences of item-level changes in a table.
DynamoDB _______ allows you to maintain First-In-First-Out records of your data. So as you go and add transactions, basically it’s given a sequence number. These sequences are stored in a stream, and the data’s broken up into shards. So it’s just time-ordered sequences of item-level changes in a table.
DynamoDB streams.
As you go and add transactions, basically it’s given a sequence number. These sequences are stored in a stream, and the data’s broken up into shards. So it’s just time-ordered sequences of item-level changes in a table.
________ is where you have
managed multi-master, multi-region replication. It’s designed where you’ve got applications that are globally distributed.
You need to have DynamoDB Streams turned on. So it’s based off DynamoDB Streams an it basically allows you to have multi-region redundancy for disaster recovery or higher availability.
Global tables
The key thing here is to remember, if you want to add redundancy to DynamoDB, you’ll need to turn on global tables. If global tables isn’t turning on, you need to make sure that you’ve enabled DynamoDB streams.
If you have a scenario where you need to migrate MongoDB from on-premise to AWS, what technology should you use?
Amazon DocumentDB
If you have a scenario where you need to migrate a big data Cassandra cluster to AWS,
what technology should you use?
AWS Keyspaces
What AWS solution is related to graph databases?
Neptune.
Note: Neptune definitely comes up a lot in the exam, but it is almost 9 times out of 10 a distractor. So just remember, if it’s not talking
about graph databases, don’t select Neptune. You only need to know what this is at a very high level.
What AWS technology provides a solutions for an immutable database?
Quantum Ledger Database technology (QLDB).
Note: If the scenario’s not talking
about an immutable database, do not select QLDB. You only need to know what this is
at a very high level.
If you have a scenario about time-series data, what AWS solution is most applicable.
Timestream
Example: you’ve got temperature sensors from all around the world at weather stations and it’s collecting the temperature every second across thousands of locations you need to store it in a database: think of Timestream.
Which AWS service would you use to host MongoDB document databases?
Amazon DocumentDB
What is a primary use case for Amazon Keyspaces?
To run Cassandra workloads on AWS
Which of the following are benefits of using RDS Multi-AZ? (Choose 3)
a. Backups are taken from a secondary copy of your data.
b. For an RDS Multi-AZ deployment with two readable standbys, in the event of a failure, both remaining standbys can take over and serve the workload (writes) from the primary.
c. If your primary database fails, you’ll automatically fail over to the secondary copy.
d. All updates or maintenance changes are applied to a secondary database. Multi-AZ rollovers are typically automatic but can be manually initiated.
a, c, d
What is the longest you can store an automatic RDS backup?
35 Days
DynamoDB is a ____ database.
Non-relational
