BatchGetItem in DynamoDB - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is the purpose of the BatchGetItem operation in DynamoDB?

BatchGetItem lets you retrieve multiple items from one or more tables in a single request. It helps save time by fetching many items at once instead of one by one.

beginner

What is the maximum number of items you can request in a single BatchGetItem call?

You can request up to 100 items or 16 MB of data in one BatchGetItem call, whichever limit is reached first.

intermediate

How does DynamoDB handle unprocessed keys in a BatchGetItem response?

If DynamoDB can't process some keys due to throttling or other reasons, it returns them in the UnprocessedKeys field. You should retry fetching these keys later.

beginner

Can BatchGetItem retrieve items from multiple tables in one request?

Yes, BatchGetItem supports fetching items from multiple tables by specifying keys for each table in the request.

intermediate

Does BatchGetItem support conditional reads or filters on attributes?

No, BatchGetItem retrieves items by primary key only and does not support conditions or filters. You get the full items for the keys requested.

What is the main advantage of using BatchGetItem in DynamoDB?

A Update multiple items at once

B Create new tables

C Delete multiple tables

D Retrieve multiple items in one request

BatchGetItem is designed to fetch multiple items from one or more tables in a single request.

What happens if some keys are not processed in a BatchGetItem response?

A They are returned in UnprocessedKeys for retry

B DynamoDB deletes those keys

C The entire request fails

D They are ignored permanently

UnprocessedKeys contains keys that DynamoDB could not process, so you can retry fetching them.

What is the maximum number of items you can request in one BatchGetItem call?

A 100

B 50

C 10

D 1000

BatchGetItem supports up to 100 items or 16 MB of data per request.

Can BatchGetItem apply filters to return only certain attributes?

A Yes, it supports attribute filters

B Yes, but only on one table

C No, it returns full items by key

D Only on indexes

BatchGetItem returns full items for the requested keys without filtering attributes.

Is it possible to fetch items from multiple tables in a single BatchGetItem request?

A No, only one table per request

B Yes, multiple tables supported

C Only if tables share the same key schema

D Only if tables are in the same region

BatchGetItem allows specifying keys for multiple tables in one request.

Explain how BatchGetItem works and when you would use it.

Think about fetching many items quickly without multiple calls.

Describe the limits and restrictions of BatchGetItem in DynamoDB.

Consider what BatchGetItem cannot do compared to other read operations.