Partition key and sort key in AWS - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is a partition key in AWS DynamoDB?

A partition key is the primary attribute used to distribute data across partitions in DynamoDB. It determines where the data is stored and helps in fast data retrieval.

beginner

What role does the sort key play in DynamoDB?

The sort key allows DynamoDB to store multiple items with the same partition key but different sort keys. It helps organize and query data within the same partition.

intermediate

How do partition key and sort key work together in DynamoDB?

Together, the partition key and sort key form a composite primary key. The partition key decides the partition, and the sort key orders items within that partition for efficient queries.

intermediate

Why is choosing a good partition key important?

A good partition key evenly distributes data across partitions, preventing hotspots and ensuring fast, scalable performance.

beginner

Can a DynamoDB table have only a partition key without a sort key?

Yes, a DynamoDB table can have just a partition key as its primary key. This means each item must have a unique partition key value.

What does the partition key in DynamoDB determine?

A The order of items within a partition

B The physical location of data storage

C The size of the database

D The encryption method

The partition key determines the physical partition where data is stored, enabling fast access.

What is the purpose of a sort key in DynamoDB?

A To sort items within the same partition key

B To distribute data across partitions

C To encrypt data

D To backup data

The sort key organizes items with the same partition key, allowing efficient queries within that partition.

Can a DynamoDB table have a composite primary key?

A Composite keys are not supported

B No, only partition key is allowed

C Only sort key is allowed

D Yes, partition key and sort key together

A composite primary key consists of a partition key and a sort key.

What happens if the partition key is not well chosen?

A Data will be encrypted automatically

B Sort key will be ignored

C Data may be unevenly distributed causing slow performance

D The database size will increase

Poor partition key choice can cause hotspots, slowing down the database.

Is it mandatory to have a sort key in DynamoDB?

A No, tables can have only a partition key

B Yes, always required

C Only for encrypted tables

D Only for global tables

DynamoDB tables can have just a partition key without a sort key.

Explain how partition key and sort key work together in DynamoDB to organize data.

Think about how data is grouped and sorted inside the database.

Describe why choosing a good partition key is important for DynamoDB performance.

Imagine how traffic flows on roads and how congestion slows things down.