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.

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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 it over a relational database, and its wrong-fit workloads.

Beginner5 min read

DynamoDB Data Types

DynamoDB's ten data types — scalars (S, N, B, BOOL, NULL), documents (M, L) and sets (SS, NS, BS), how they look in DynamoDB-JSON, and which can be a key.

Beginner4 min read

DynamoDB JSON & Marshalling

DynamoDB JSON and marshalling — why every value is wrapped in a type tag, how the format 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, and how to model around unbounded item growth.

Beginner5 min read

DynamoDB Item-Based Actions

DynamoDB item-based actions — GetItem, PutItem, UpdateItem and DeleteItem each address one item by its full primary key, and 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 vs Eventually Consistent Reads

DynamoDB strongly consistent vs eventually consistent reads — what each guarantees, the 2× RCU cost of ConsistentRead, and why a GSI is eventual-only.

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.