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Comment by estsauver | Hacker News Reader

I'm slightly confused, is this the same as the existing point-in-time restore that's available for other RDS instances?

Edit: Main difference seems to be new cluster vs. in place.

I believe this is special because it pauses, backtracks and resumes your existing cluster. No new cluster provisioning time or configuration changes

Similar but from what I understand it allows granularity down to seconds instead of minutes and new cluster provisioning in minutes rather than potentially hours.

Speed of new cluster provisioning is neat, amazon-rds console currently shows the option to do a point of time restore down to the second. Maybe that's actually not available already and they're truncating to the latest backup?

Edit: I guess it's also nice that it's in place. Some people probably don't have the flexibility to easily point applications at a new cluster in a repeatable way, so that may help folks prevent down time.

Point in time restores to the last daily snapshot and replays logs since that snapshot; this can take quite some time (hours) if your database has a lot of writes, especially if the snapshot was 23 hours ago. The blog post doesn't quite make it clear but I would hope that backtracking is somewhat quicker than this method.

No; look at the screenshots. You can pick any point in time given the window you request.

I see that option in well already for AWS-RDS postgres point in time restore.

That usually what point in time restores allow, by using snapshots as a base and WAL since then.

I think the main difference is that restore will create a new DB instance, whereas backtrack updates the state of the DB instance in place. It is also probably a lot faster than restoring.

You're right - it is a lot faster. That's because we don't change any data blocks. we just mark a portion of the log to be ignored.

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