Databases

Question 1

Database functionality to consider when choosing

Answer 1

1. Scale
2. Operations
3. Replication
4. Transactions

Question 2

Themes associated with SCALE

Answer 2

• Vertical scaling
• Horizontal scaling
• Sharding

Question 3

Themes associated with OPERATIONS (cost of operating a database)

Answer 3

• HW breakdowns
• SW upgrades
• EOL (End of Life)
• Tweaking
• Rebuild indexes

Question 4

Themes associated with REPLICATION

Answer 4

• Read only replicas

- Disaster recovery replicas

Question 5

Themes associated with TRANSACTIONS

Answer 5

• ACID

- CAP theorem

Question 6

NoSQL vs SQL

Answer 6

todo

Question 7

SQL DBs on the market (2020)

Answer 7

• Google’s Cloud Spanner “no compromise database”

Question 8

NoSQL DBs on the market (2020)

Answer 8

todo

Question 9

Google’s Cloud Spanner

Answer 9

Pros

• Relational semantics w/ Schemas, ACID transactions, SQL
• Horizontal scale (99.999% SLA) –> grow to arbitrarily large number of instances

Cons

• hard to “lift and shift” for migration
• application is responsible for a lot

more info: https://www.youtube.com/watch?v=rRVmg5t6TZs

Question 10

RDBMS

Answer 10

Relational Database Management System

RDBMSs use SQL (and variants of SQL) to manage data in large tables.

e.g. MySQL, PostreSQL, Oracle DB, SQL Server

Question 11

ORM

Answer 11

Object-relational mapping

A programming technique for converting data between incompatible type systems using object-oriented programming languages.

It’s the idea of being able to write queries (e.g. SELECT * FROM users WHERE email = ‘test@test.com’;) using the ORM paradigm of your preferred programming language (INSTEAD of using SQL)

“ORM” generally refers to a library qhich implements this technique.

https://blog.bitsrc.io/what-is-an-orm-and-why-you-should-use-it-b2b6f75f5e2a

Question 12

Google Cloud Platform DB Options

Answer 12

In-Memory
- Cloud Memorystore (managed redis)

Non-relational

• Cloud Datastore/Cloud Firestore (serverless, document database service)
• Cloud Bigtable (Wide-column database service)

Relational

• Cloud SQL (Managed MySQL & PostgreSQL)
• Cloud Spanner (Scalable relational database service)

Object
- Cloud Storage (Object storage, data lake)

Warehouse
- BigQuery (Enterprise data warehouse)

Question 13

Bigtable (Google Cloud)

Answer 13

non-relational cloud DB offered by google cloud. Super high throughput, low latency reads & writes

Good for IoT data, streaming data, time series data, backend store for graph stores.

• *Scaling: Horizontally scalable
• *Replication: eventually consistent
• *Queryability: point lookup or table scan