In the previous chapter, we learned to create a secondary index for a table and its role in retrieving the items efficiently. In the long run, knowledge of the secondary index is useful only if we know how to use it for retrieval. Item retrieval can be done in DynamoDB using two operations called query and scan. Similarly we also discussed sharding. In this chapter, we will learn about parallel scanning, which makes use of the sharding concept. The primary objective of any database (whether it be NoSQL or SQL) is to provide easy storage and faster retrieval of data. So far, we have discussed various configurations that can be added to our table, such as adding an index, specifying the primary key, and so on. In this chapter, we will cover the following topics:

First, we will discuss the query operation, which makes use of the hash and range key values to retrieve the items. Then we will...