Amazon DynamoDB

• DynamoDB is a NoSQL fully managed Database-as-a-Service (DBaaS) product available within AWS.

• Local Secondary Indexes (LSI) and Global Secondary Indexes (GSI) allow for an alternative presentation of data stored in a base table.

• LSI allow for alternative SK's whereas with GSIs you can use alternative PK and SK.

• DynamoDB Streams are a 24 hour rolling window of time ordered changes to ITEMS in a DynamoDB table

• Streams have to be enabled on a per table basis , and have 4 view types

• KEYS_ONLY

• NEW_IMAGE

• OLD_IMAGE

• NEW_AND_OLD_IMAGES

• Lambda can be integrated to provide trigger functionality - invoking when new entries are added on the stream.

• DynamoDB Global Tables provides multi-master global replication of DynamoDB tables which can be used for performance, HA or DR/BC reasons.

• DynamoDB Accelerator (DAX) is an in-memory cache designed specifically for DynamoDB. It should be your default choice for any DynamoDB caching related questions.

• Amazon DynamoDB Time to Live (TTL) allows you to define a per-item timestamp to determine when an item is no longer needed.
• Shortly after the date and time of the specified timestamp, DynamoDB deletes the item from your table without consuming any write throughput. TTL is provided at no extra cost as a means to reduce stored data volumes by retaining only the items that remain current for your workload’s needs