Document Databases

Question 1

Characteristics of Document DB

Answer 1

• data needs to be like document structure
• schema flexibility
• easy to load all data

Question 2

How to select which database to use?

Answer 2

data has 1:M (tree structure) or no relations => document db

transaction data with 1:1 or simple M:M => relational

complex M:M => graph database

Question 3

Data Query Languages

Answer 3

Imperative

• put down exact instructions

• specify data pattern required + what conditions must be met and transformations
• db engine figures out the best execution plan

Map Reduce