An Introduction to NoSQL
Thameera Senanayaka
Allion Technologies
- SQL Server
- MySQL
- PostgreSQL
- Oracle
- SQLite
Databases we use
Relational Databases
Relational Databases
- Tables
- Schemas & Normalization
- SQL to query data
What is NoSQL?
- Any database that is not a relational database
- Schema-less
- Running well on clusters
NoSQL !=
NoSQL ==
{
_id: xxxxx,
article_id: yyyy,
time: yymmdd,
text: abcde
}
Use Case - Comments in a blog
Use Case - Comments in a blog
{
_id: xxxxx,
article_id: yyyy,
time: yymmdd,
text: abcde,
author: {
id: xxx,
name: 'user'
}
}
Use Case - Comments in a blog
{
_id: xxxxx,
article_id: yyyy,
time: yymmdd,
text: abcde,
author: {
id: xxx,
name: 'user'
},
replies: [
{ ... },
{ ... }
]
}
Use Case - Comments in a blog
{
title: 'some title',
post: 'post',
date: yymmdd,
comments: [
{
_id: xxxxx,
time: yymmdd,
text: abcde,
author: {
id: xxx,
name: 'user'
},
replies: [
{ ... },
{ ... }
]
},
{
...
}
]
}
Types of NoSQL databases
1. Document Store
Types of NoSQL databases
2. BigTable
Types of NoSQL databases
3. Key-value store
Types of NoSQL databases
4. Graph
SQL | NoSQL |
---|---|
Rows | Documents |
Tables | Columns |
Requires a schema | Schema-less |
JOINs | No JOINs (data is denormalized) |
Transactional guarantees | No guarantees for multiple documents |
Can be scaled (with some effort) | Excellent performance & scalability |
SQL querying | JSON data object querying |
Why NoSQL?
- Big data
- Real time analytics
- IoT
- Rapid development
Final words
- None is better than the other
- Right tool for right job
- Don't think everything is a nail for your hammer
Thank you!
Introduction to NoSQL
By Thameera
Introduction to NoSQL
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