Welcome back! In our previous lessons, we covered basic data retrieval operations like GetItem and BatchGetItem. Today, we’re advancing to more complex retrieval methods—Query and Scan. These operations are vital for efficiently managing and querying large datasets within DynamoDB. We'll be using the Books table for our examples, which has a primary key consisting of year (partition key) and title (sort key).

The Query operation in DynamoDB allows you to retrieve multiple items by specifying exact or conditional matches on the primary key attributes. For example, you can retrieve all books published in a specific year or filter further by titles within that year using sort key conditions.

The Scan operation examines every item in a table and returns all data attributes by default. While powerful, Scan can be inefficient and costly in terms of read capacity units, especially for large tables.