In the previous chapter, we saw how to work with DynamoDB SDK. We discussed table creation, item insertion, and updating a table using Java SDK. During table creation, we used two functions to create the local and global secondary indexes that we will discuss now.
Projection helps the programmer to decide which attributes have to be added to the secondary index.
Understanding the secondary index and projections should go hand in hand because of the fact that a secondary index cannot be used efficiently without specifying projection. In this chapter, we will cover the following topics:
Global secondary indexes
Local secondary indexes
The use of projection in DynamoDB is pretty much similar to that of traditional databases. Before learning about projection, go through Chapter 2, DynamoDB Interfaces, and Chapter 3, Tools and Libraries of AWS DynamoDB, which deal with the DynamoDB data model where we use some basics...