Fundamentals

Before you model relationships or tune indexes, you need the primitives DynamoDB actually gives you: the value types you can store, how items group on disk, and the key that decides where each item lives. Get these wrong and every later pattern fights you.

Coming from SQL, the surprises start here. There are no columns and no schema — just typed attributes per item — and the primary key isn't a convenience, it's the physical layout of your data.

0 of 9 readQuiz

When to Use DynamoDB (and When Not To)

When to use DynamoDB (and when not to) — the access-pattern, scale, and cost signals that favor DynamoDB over a relational database, and the workloads where it's the wrong fit.

Beginner5 min read

DynamoDB Data Types

DynamoDB data types explained — the scalar (S, N, B, BOOL, NULL), document (M, L) and set (SS, NS, BS) types, how they appear in DynamoDB-JSON, and how each is sized.

Beginner3 min read

DynamoDB JSON & Marshalling

DynamoDB JSON and marshalling — why DynamoDB wraps every value in a type descriptor like {"S":"..."}, how it differs from plain JSON, and how to convert between the two.

Beginner4 min read

The DynamoDB Item Size Limit (400 KB)

The DynamoDB 400 KB item size limit — what counts toward it, how attribute names and nesting add up, why the cap exists, and how to model around unbounded item growth.

Beginner4 min read

DynamoDB Item-Based Actions: GetItem, PutItem, UpdateItem, DeleteItem

DynamoDB item-based actions — GetItem, PutItem, UpdateItem and DeleteItem — the four single-item operations, how each addresses an item by its full primary key, and how they differ from Query and Scan.

Beginner5 min read

DynamoDB Item Collections

What a DynamoDB item collection is — every item sharing a partition key — why it's the unit of efficient Query reads, and the limits to watch out for.

Beginner8 min read

DynamoDB Composite Primary Key

A DynamoDB composite primary key is a partition key plus a sort key — it groups related items together and unlocks range queries a simple key can't do.

Beginner6 min read

DynamoDB Strongly Consistent vs Eventually Consistent Reads

DynamoDB strongly consistent vs eventually consistent reads — what each guarantees, why eventual reads can return stale data, the 2× RCU cost of ConsistentRead, and which indexes support strong reads.

Intermediate5 min read

Knowledge checkTake the quiz

Check what you’ve learned in this section.

Start with data types if you're brand new; jump to composite primary keys if you already know the value model and want the part that drives every access pattern.

Want to poke at real items as you read? Try DynoTable and inspect a table's keys and collections directly.