DynamoDB – Time To Live (TTL)

• Automatically removes items from a table when a designated expiration timestamp is reached.

• Helps control storage costs and manage data lifecycle without manual cleanup jobs.

How It Works

• You enable TTL on a specific attribute in the table (e.g., ExpTime).

• Value must be a UNIX epoch timestamp (in seconds).

• When the current time passes this value, DynamoDB marks the item as expired.

• Deletion happens in the background, usually within 48 hours (best-effort, not guaranteed immediate).

Use Cases

• Session management (auto-expire inactive sessions)

• Event logs with a retention period

• Regulatory compliance (automatic deletion after retention window)

Important Notes

• Expired items are not returned in queries or scans once deleted.

• TTL deletes are free and do not consume write capacity.

• Deleted items can still appear in DynamoDB Streams before removal.