RMAN backup generates traces in Oracle 12.2.0.1

Oracle 12.2.0.1 seems to be the “tracing” release without further patch or parameter treatments. After posting about MMON unconditional traces in Oracle 12.2.0.1 a day ago, I received a couple of comments either on the blog, via LinkedIn or Twitter regarding other trace facilities in Oracle Database 12.2.0.1. One of them is the case that RMAN backup generates traces in Oracle 12.2.0.1. And please, very important upfront: Oracle Database 12.2.0.1 is a very stable and reliable release based on all the customer feedback Roy and I received so far. For instance, when we check for optimizer issues causing trouble in…

Upgrade to Oracle 12.2.0.1: Check your DEFAULT temporary tablespaces

One of the reasons why I have this blog is simply to stay in touch with smart people using Oracle and telling me about issues I haven’t seen before. Thanks to Tyler Van Vierzen I learned that an upgrade to Oracle 12.2.0.1 may alter the default local temporary tablespace. Upgrade to Oracle 12.2.0.1: Check your DEFAULT temporary tablespaces Tyler did contact me on Twitter: “Curious if you’ve seen this… Seeing new “local temp tablespace” set to SYSTEM for some users after 12.2 upgrade. But not all. No discernable pattern. Some null (so default to their temp tablespace), some set equal…

Optimizer Issue in Oracle 12.0.1.2: “Reduce Group By”

DBAs biggest fears I’d guess are Optimizer Wrong Query Results bugs as usually the optimizer does not write a message into the alert.log saying “Sorry, I was in a bad mood today …”. The Oracle Database Optimizer is a complex piece – and in Oracle 12c it delivers great performance results. Plus (my personal experience when you know what to do) it is more predictable which I like a lot when changing databases from one to another release. But due to its complexity sometimes we see issues – and sometimes it is necessary to switch off tiny little pieces until…