Remove Underscore Parameters not only before you upgrade

Underscore parameters are a wonderful thing in Oracle. They are treated like a secret. But you can view them of course. Everybody can. Make a guess how many underscore parameters exist in Oracle 12.2.0.1.0. You’ll find the answer at the end of this blog post. But why should you remove underscore parameters not only before you upgrade? I’d like to explain below why underscores, especially too many of them, may cause a lot of trouble. Therefore, housekeeping is very important. Remove Underscore Parameters not only before you upgrade This is from a recent upgrade from Oracle 12.1.0.2 to Oracle 12.2.0.1…

Oracle 12.2 underscores appear in SPFILE – be aware when you flashback

I did blog in the past weeks about Fallback Strategies with Flashback Database. But two of my reference customers came across an interesting issue when they tried to fallback: Oracle 12.2 underscores appear in the SPFILE – magically – and prevent the fallback using the existing SPFILE. Oracle 12.2 underscores appear in SPFILE – be aware when you flashback In one case it happened during a test, in the other case it happened during a live fallback after the Data Guard Broker has interfered with the upgrade causing real trouble. In both cases the SPFILE sits in ASM. Both customers…