Book Image

DynamoDB Applied Design Patterns

By : Uchit Hamendra Vyas
Book Image

DynamoDB Applied Design Patterns

By: Uchit Hamendra Vyas

Overview of this book

Table of Contents (17 chapters)
DynamoDB Applied Design Patterns
Credits
About the Authors
About the Reviewers
www.PacktPub.com
Preface
Index

Scanning tables


A scan operation evaluates each and every item in the table. Usually, it retrieves every item (with all the attributes along with all the items) of the table. This is the reason why the scan operation is not preferred. It is always recommended that you use query whenever possible. However, it is possible for us to retrieve only specific attributes using the AttributesToGet parameter, similar to the way we saw with query. Additionally, we can filter the number of items retrieved by the scan using the scan filter condition. For instance, if we assume that there are 100 items available in the table, and if the scan filter filters out 10 items using strong consistent read (which consumes a maximum of 1 KB capacity units per item), can you tell how many capacity units were eaten up by this scan operation? If you think it consumes 100 capacity units, then you're in the right boat, because the capacity unit is not a measure of how many items (hoping that every item is less than...