01 - Databases in the Real World

Question 1

List

Design Considerations

3

Answer 1

1. Performance
2. High Availability
3. Backup and Recovery

Question 2

List

Performance features required for the workload

4

Answer 2

1. Required latency
2. IOPS
3. Read/write throughput
4. Concurrency

Question 3

Define

latency

Answer 3

• how quickly users need a response
• amount of time needed to complete an activity

Question 4

Define

IOPS

Answer 4

Input/output operations per second
How often users are reading and writing data to the database
(e.g. 10 reads per second)

Question 5

Define

concurrency

Answer 5

• How many users are active at the same time
• How many active users are accessing the same data at the same time?

Question 6

How to improve latency and read/write throughput?

Answer 6

provision more IOPS when configuring the database

Question 7

Differentiate

IOPS vs Throughput

Answer 7

• Throughput - measurement of bits or bytes per second that can be processed by a storage device
• IOPS - number of read/write operations per second.

Both IOPS and throughput can be used together to describe performance.

Question 8

Define

High Availability

Answer 8

At any point where you try to access the database, it always gives the data needed (non-error response)

Question 9

List

High Availability features required for the workload

3

Answer 9

1. Read replicas
2. Clustering
3. Geo-distributed deployments

Question 10

Define

Read replicas

Answer 10

Create read-only copies
* Updates made to the source database are asynchronously copied to read replicas
* provides scalability
* can be promoted to a standalone database instance

Question 11

Define

Clustering

Answer 11

• Some nodes, that you can write and process
• for write- and process-heavy workloads.
• 1 cluster = 1+ compute nodes replicated across multiple Availability Zones
• to gain increased read scalability and failover protection.

Question 12

Geo-distributed deployments

Answer 12

for databases across diff places
* If you deploy data in US, you are bound by US laws
* Ex. if theres a threat to natl security, they can look into data servers in the US
* You can read/write from other places, or pwedeng read lang ganun

Question 13

Explain

Backup and Recovery

Answer 13

• When disaster happens, need to make sure ur data is still accessible & u don’t lose data
• Have multiple copies of data, so that when one copy is ruined, you still have other copies available

Question 14

Define

RPO

Answer 14

returning point objective
getting data when the disaster happens → no data loss

Question 15

Define

RTO

Answer 15

Returning Time Objective
* time it takes to go back to RPO
* Best RTO: as soon as possible

Question 16

List

Workload requirements

3

Answer 16

1. Data Storage
2. Data volume, velocity, and variety
3. Data Usage

Question 17

Data Storage Types

4

Answer 17

1. File system
2. Object store
3. Relational database
4. Nonrelational database

Question 18

Differentiate

Data volume, velocity, and variety

Answer 18

Data volume: size of individual items being written into workload AND total size of all items within workload.

Data velocity: how fast writes and reads are
* can cause data bottlenecks if your system is not properly tuned.

Data variety: indicator of the type of database or databases you may need for your workload.
* Before: structured data in relational databases; semistructured in nonrelational databases; unstructured data in file system.
* lines are more blurred now

Question 19

How will the data in your workload be used?

5

Answer 19

SQL data organization
* OLTP or OLAP
* DSS
* Data warehouse

NoSQL access patterns
* IoT
* Session state

Question 20

T/F

In an ideal scenario, the application server communicates with the database server over a public network.

Answer 20

F
private network