Database Types

There are many database types available. They have different characteristics for different use cases. Each of them has benefits and disadvantages

▪ Key Value Databases

▪ Relational Databases

▪ Graph Databases

▪ Wide Column Databases

▪ Document Databases

▪ Search Databases

Key Value Databases

Characteristics

▪ Data is saved in key-value pairs

▪ unique key

▪ no joins

▪ in-memory

Best for

▪ Caching

▪ Message Queue

very fast

limited storage

no primary database

Wide Column Databases

if you need to store more complex key value date you can use column DB you have the same key, but value is divided multiple column

Characteristics

▪ A two-dimensional key-value store

▪ Data is saved in tables, rows, and columns

▪ Names and format can vary from row to row (schema-less)

▪ Queries similar to SQL

Best for:

▪ Time-Series

▪ IoT-Records

• historical -records

scalable

no joins

limited compared to relational DB

no primary DB

Document Databases

Characteristics

▪ Data is stored as JSON-like documents

▪ Schema-less

▪ No joins

▪ Denormalized

Best for:

▪ Mobile Apps

▪ Game Apps

▪ CMS

▪ Most Apps

faster to read

easy to get started

primary database

slower writes

Relational Databases

Characteristics

▪ Data is stored in tables, rows, and columns

▪ Schema (schema and data types need to be created first)

▪ Normalized to avoid duplicated data

▪ Most used in industry

• to store structured data

Best for:

▪ Structured data

ACID

easy to get started

primary database

❌ difficult to scale

❌ unstructured data

ACID = Atomicity, Consistency, Isolation, Durability

▪ No half-changes are updated in database

▪ Either ALL changes get applied or NON

💡 SQL vs No-SQL

Because relational or SQL databases are so popular, often we talk about SQL vs No-SQL, meaning all the other database types, which are schema-less

BEST FOR:

• GRAPHS

• PATTERNS