Understanding backup fundamentals
The backup and restore functionalities in DynamoDB operate independently of actual table reads and writes. When a backup is requested or performed, it does not impact the application’s access to the table in terms of latency or throughput. Similarly, when a restore is executed against a DynamoDB backup, it is performed in isolation from the source DynamoDB table. This isolation is due to DynamoDB’s use of write-ahead logs, which record every write operation performed on the table. These logs are used to perform backup and restore functions and ensure durability and continuous data correctness checks. The following figure is an illustration of a typical write-ahead log, presented for learning purposes and not as an exact representation of the logs used within DynamoDB:
Figure 11.1 – Example write-ahead log structure
As shown in Figure 11.1, at a high level, each write-ahead log entry contains details...
