database Flashcards

1
Q

6 Relational databases on AWS

A

Oracle, SQL server, mysql, postgressql, Amazon aurora, Maria DB

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

RDS has two key features

A

Multi AZ - for disaster recovery

Read replicas for performance

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Non relational database

A

Collection is a table
Inside a collection is a document which is a row
Key value paris = fields ( columns)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What is data warehousing

A

It is used for business analysis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

OLTP vs OLAP

A

OLTP - find a specific order in database

OLAP - Netprofit for America compared to Asia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Redshift

A

Amazon Data warehousing solution

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Elastic cache support two in memory open source cache engines

A

REDIS and memcached

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

RDS instance

A

you cannot patch the RDS instance. RDS is not serverless. Exception is Auroro . Aurora is serverless

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Automated backups

A

Recover to any point in time within the rententioin period. Retention period is between one and 35 days.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Automated backups method

A

Full snapshot + transactions logs throughout the day.

This allows you to do a point in time recovery down to a second within the rentention period.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Automated backup s3 storage

A

is free and is equal to the size of the RDS DB

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Backup scheduling

A

Taken during backup window, storage io may be suspended. May experience elevated latency

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Restore will restore to a brand new RDS isntance

A

will result in a different end point

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Data at rest is encrypted

A

Encryption uses KMS service

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Multi-AZ

A

is for disaster recovery only. It is not for improving performance.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Multi AZ is available for

A

SQL server, Oracle, MySQL, postgres, MariaDB

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Read replicase are available for

A

MySQL, Postgres, mariaDB, Oracle, Aurora

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Read replica characteristics

A

Used for performance not for DR, You must have automatic backup enabled to have read replicas, Upto 5 read replicas. You can have read replicas of read replicas.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Read replica characteristics2

A

Read replicase with multi-AZ turned on,
You can have read replicase of Multi-AZ source DB
RR can be promoted to its own DB. This breaks replication
You can have read replica in a second region

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What do you have to type to delete a RDS

A

delete me

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Dynamo DB

A

is a no-sql database for apps that need consistent single digit millisecond latency at any scale

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Dynamo DB data models

A

both document and key-value data modesl

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Dynamo DB characteristics

A

stored on SSD, spread across 3 different geographically distinct data centers

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Read consistency types

A

Eventual consistent reads after 1second, strongly consistent reads

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Read consistency types
Eventual consistent reads after 1second, strongly consistent reads
26
Redshift
fully managed petabyte scale db service. $.25 per hour with no commitments. $1000 per TB per year
27
Redshift can be configured as
Single node(160Gb), Multi-node( Leadernode and Compute node)
28
Redshift backups
Enabled by default with 1 day retention period Max retention period=35 days 3 copies, Original, on compute nodes, S3 It can async replicate your snapshots to S3 in another region.
29
Redshift pricing
compute node hours . 1Unit per node per hour, Backup Data transfer ( only within a VPC, not outside)
30
Redshift pricing
compute node hours . 1Unit per node per hour, Backup Data transfer ( only within a VPC, not outside)
31
Redshift availability
Currently only available in 1AZ | Can restore snapshot to new AZ for DR
32
Amazon Aurora
MySQL compatible RDB. provides speed and availability of commercial DB and cost effectiveness of open source DB.
33
Aurora price
1/10 of a commercial DB
34
Aurora performance
5 times better performance than MySQL. Built by Amaxon from scratch.
35
Basics of Aurora
Start with 10GB and scales in 10GB increments upto 64TB
36
Compute resources for Aurora
Can scale up to 32vCPUS and 256Gig memory
37
Aurora availability
2 copies of data in each AZ, with a min of 3AZ, 6 copies of your data. It is not availabilty in all regions yet
38
Scaling Aurora
Can handle loss of 2 copies of data without affecting write availability and can handle 3 losses without affecting read availability
39
Aurora data blocks
self healing . repeatedly scanned and repaired automatically
40
Auroro replicas
Aurora replicas(currently 15) , MySQL read replicase(currently 5)
41
Backups with Aurora
Automated backup is always enabled. Backups do not impact performance.
42
Snapshots with Aurora
This also does not impact performance and you can share snapshots with other AWS accounts.
43
Aurora nodes
Writer node and reader nodes are created in different AZ. It has a different DNS endpoints
44
Elasticcache
webserivce that makes it easy to deploy operate and scale in-memory cache.
45
Redis vs Memcached
Advanced data types, sorting data sets, pub sub capabilities, persistence, Multi-AZ, backup and restore
46
2 types of RDS backsups
Automated backups and snapshots
47
Only RDS which does not support read replica
SQL Server
48
Amazon RDS Provisioned IOPS storage with a Microsoft SQL Server database engine, what is the maximum size RDS volume you can have by default
16 TB
49
How many copies of my data does RDS - Aurora store by default
6
50
When you add a rule to an RDS DB security group
Technically a destination port number is needed, however with a DB security group the RDS instance port number is automatically applied to the RDS DB Security Group
51
Which of the following data formats does Amazon Athena support
"JSON", "Apache Parquet", "Apache ORC" amongst others, but "XML" is not a format that is supported.
52
Redshift is relational or not
relational supports OLAP
53
You are hosting a MySQL database on the root volume of an EC2 instance. The database is using a large number of IOPS, and you need to increase the number of IOPS available to it. What should you do
Add 4 additional EBS SSD volumes and create a RAID 10 using these volumes.
54
What happens to the I/O operations of a single-AZ RDS instance during a database snapshot or backup
I/O may be briefly suspended while the backup process initializes (typically under a few seconds), and you may experience a brief period of elevated latency.
55
What data transfer charge is incurred when replicating data from your primary RDS instance to your secondary RDS instance
no charge
56
DynamoDB availability
DynamoDB only being single availability zone by default making this the correct answer
57
DynamoDB primary key
can either be a single-attribute or a composite, user-defined primary key is allowed too
58
Provisioned IOPS
Provisioned IOPS becomes important when you are running production environments requiring rapid responses, such as those which run e-commerce websites. Without high performant responses from an RDS instance page loads of the website could suffer resulting in loss of business. If your workloads are not latency sensitive or you are running a test environment the additional cost of provisioned IOPS will not be cost beneficial to your project.
59
In RDS, changes to the backup window take effect
Immediately
60
In RDS, what is the maximum value I can set for my backup retention period
35 days
61
Which of the following DynamoDB features are chargeable, when using a single region
There will always be a charge for provisioning read and write capacity and the storage of data within DynamoDB, therefore these two answers are correct. There is no charge for the transfer of data into DynamoDB, providing you stay within a single region (if you cross regions, you will be charged at both ends of the transfer.) There is no charge for the actual number of tables you can create in DynamoDB, providing the RCU and WCU are set to 0, however in practice you cannot set this to anything less than 1 so there always be a nominal fee associated with each table. Further information: https://aws.amazon.com/dynamodb/pricing/