Forced apply lag determines the amount of time we wait after the transactions commit on the primary database to apply those changes on the standby database. The logs are shipped to the standby, which means the logs for the truncate were present on the ASB server, but had not yet been applied check this out.
http://energiamunka.hu/map10 I clearly remember, during the design phase, recommending the customer keep this database in a perpetual lag state, but they pushed back. After some discussion about User Error, they agreed that since it would not affect the reporting they wanted to offload, we could maintain a 120 minute lag behind production.
With this knowledge in hand, we set out to find the fastest way to recover the missing data. It turns out that the two truncated tables are only used when certain inbound transactions are received, and only a few of those transactions were received since the error occurred. This was the best case scenario for such an ‘oops’ moment learn more here.
http://serviceoffice.co/mapca1 This entire episode took place within a 2 hour window, and they did not experience any downtime or lose a single row of data related to this user error.
What I learned that day as a DBA is that you can never have too many ways to get your data back. As a consultant, I learned that our customers pay us for our knowledge and expertise, and sometimes they need some extra guidance in order to see what I see from our years of experience in the industry (like having a standby that lags behind production). And as a businessman, I learned that putting flashback in place is a key element to maintain minimal downtime. I believe if we had flashback we could have put the data back in less than an hour.