Two weeks ago I published a blog post about Parameter Recommendations for Oracle Database 18.104.22.168. And I took it down a day later. Why that?
I’ve got a lot of input from external sources for the “Parameter” blog post. And I’d like to thank everybody who contributed to it, especially Oracle ACE Ludovico Caldara.
Generally there was a bit of a misunderstanding internally about whether we should “advertise” underscore parameters to cure some misbehavior of the database. In 99% of all cases I’d agree that underscores are not a good solution – especially when it comes to database upgrades as our slide deck still contains a real world example about what happens when you keep old underscore parameters in your spfile. It can not only slow down the entire upgrade but also makes it very hard for Oracle Support to reproduce issues in case of something going the wrong direction.
But in some situations an underscore seems to be the only remedy in cases where a patch is not available for a particular release – the release you are using at the moment. And even if a patch is available or if the fix is available in a future PSU or BP that does not mean necessarily that one can apply it for several reasons.
We still have a lot of very productive discussions going on internally between many groups. That is very good as it means that we have plenty of smart people around, especially in Oracle’s Database Development 🙂
Furthermore we agreed that the Optimizer PM team will take over the part of my (taken down) blog post targeting wrong query results and other optimizer topics. We are in constant exchange and I’ll link it as soon as something gets published.