What are DynamoDB Projections?
As its name suggests, the attributes in a table projected to the index are the projections. (Similar to the GROUP BY operation in SQL). Projections can exclude all the unnecessary items and reduce the overall size of the payload returned by the API.
We have to define the projected attributes each time we create a local secondary index. Each index must have minimally three attributes: table partition key, index sort key, and table sort key.
