Amazon DynamoDB supports GET/PUT operations by the help of a user-defined primary key. The primary key is the only required attribute for items in a table and it uniquely identifies each item.
A primary key can either be a single-attribute partition key or it can be a composite partition-sort key. A single attribute partition primary key can be explained as, for example, “UserID”. By the help of UserID one can quickly read and write data for an item associated with a given user ID.
A composite partition-sort key is indexed as a partition and a sort key element. For example, a composite partition-sort key could be a combination of “UserID” (partition) and “Timestamp” (sort). Holding the partition key element constant, user can search across the sort key element to retrieve the required items.
Hope you got a brief idea about the types of query that are supported by DynamoDB. You must keep this in mind that, you can write your queries based on these two key methods.