Automatic Historical Tracking of Data in Oracle Using Flashback Data Archive

[@ronangustavodimarcosaletti798]

Hi Chris, one question about 12c/19c standard versions, does this feature works there? what about license, is it free on 12c/19c standard edition? Thanks a lot!

[@MrPULKITMATHUR]

Hi Chris, one question about how quickly this data can be accessed in large DBs. We have a requirement where a frontend user would need to check historical data on a regular basis in the frontend application. If we use "Flashback Data Archive", is the data stored in some kind of "Archive" and it would be costly to make the call for accessing the historical data very frequently? Or can the historical data be accessed with the same "cost" as accessing other operational data from other operational tables?

[@chrissaxon3111]

Yes, the data are stored in an archive - real tables, managed by the database. You can query them directly if you want; but it's better to get the data through the "as of" syntax. If you look at the plan of an "as of" query, you'll see a scary looking plan with lots of unions. The cost of doing these queries is the classic "it depends" answer. If your app does lots of insert/update/deletes, there will be a lot of history to wade through. So the query may take a while. If it's read and/or insert-mostly, there's only the insert "changes" to see. Ultimately it's just a query. Albeit one controlled by the database. So you'll need to test to see how it performs in your app. Like all SQL, the overall size is irrelevant to how fast it is. It's how much data the query you run processes.