Stage 1 · Lesson 1 of 6
Structured, semi-structured and unstructured data
Data comes in three broad shapes. fits neat rows and columns with known types: users, orders, marks, payments. Semi-structured data has a shape, but it varies from record to record, like JSON from an API, product attributes that differ between phones and shoes, or form answers.
Unstructured data has no fields at all: images, audio, PDFs, long free text. Each shape has a natural home. Structured data suits a , semi-structured data suits or a , and unstructured files belong in with only their key and details saved in the database. Most real apps hold all three.
Common trapchoosing one database for its reputation and then forcing every shape into it, such as storing photos inside table rows.
A question to check yourself, an AI practice session and 1 cheat sheet entry come with the full roadmap. Unlock
Resources for this stage
Start with· follow one of these
- CoursePaidGrokking Database Fundamentals for Tech Interviews
Design Gurus · Beginner · Subscription
A structured tour of database types, SQL versus NoSQL, ACID and indexes before you compare products
- CourseFreeCS50's Introduction to Databases with SQL
Harvard University · Beginner
Free Harvard course: the first lectures show how real data is modelled and queried