Return values on write in DynamoDB - Cheat Sheet & Quick Revision

Recall & Review

beginner

What does the ReturnValues parameter do in a DynamoDB write operation?

It controls what data is returned after a write operation like PutItem, UpdateItem, or DeleteItem. You can get back the old item, the new item, or nothing.

intermediate

Name the possible values for ReturnValues in DynamoDB write operations.

• NONE: Returns nothing (default).
• ALL_OLD: Returns the item as it was before the write.
• UPDATED_OLD: Returns only the updated attributes before the write.
• ALL_NEW: Returns the item as it is after the write.
• UPDATED_NEW: Returns only the updated attributes after the write.

beginner

If you want to see the new values of an item after an update, which ReturnValues option should you use?

Use ALL_NEW to get the entire item as it looks after the update, or UPDATED_NEW to get only the attributes that changed.

beginner

What is the default behavior of ReturnValues if you don't specify it in a write operation?

By default, ReturnValues is set to NONE, so the write operation returns no data about the item.

intermediate

Why might you want to use ReturnValues in a real-world application?

It helps you confirm what changed or existed before the write without making a separate read request. For example, you can get the old item before deleting it or see updated fields after an update.

What does ReturnValues: ALL_OLD return after a DeleteItem operation?

A The item as it was before deletion

B The item as it is after deletion

C Only the updated attributes after deletion

D No data is returned

ALL_OLD returns the entire item as it was before the delete operation.

If you want no data returned after a write operation, which ReturnValues should you use?

A ALL_NEW

B NONE

C UPDATED_NEW

D ALL_OLD

NONE is the default and returns no data after the write.

Which ReturnValues option returns only the attributes that were updated, after an update?

A ALL_OLD

B ALL_NEW

C UPDATED_OLD

D UPDATED_NEW

UPDATED_NEW returns only the updated attributes after the update.

Can ReturnValues be used with PutItem to get the new item after insertion?

A Yes, use ALL_NEW

B No, it only works with UpdateItem

C Yes, use ALL_OLD

D No, PutItem never returns data

Using ALL_NEW with PutItem returns the item after insertion.

What is a practical benefit of using ReturnValues in a write operation?

A It speeds up the write operation

B It encrypts the data automatically

C It reduces the need for a separate read request

D It backs up the item to another table

Getting return values lets you see changes without an extra read call.

Explain the purpose of the ReturnValues parameter in DynamoDB write operations and list its main options.

Think about what you want to see after you change data.

Describe a scenario where using ReturnValues would help avoid an extra read request.

Imagine you want to confirm what changed immediately.