Author Archives: Bobby

I was trying to recreate the scenario where a 12c container database is flashed back to a SCN before the point that I recovered a pluggable database to using point in time recovery. I got this ugly ORA-00600: RMAN> recover … Continue reading →

I got the newly available Kaplan test prep software for the Oracle 12c OCP upgrade exam. I took the test in certification mode when I was tired at the end of the day some day last week and got 44% … Continue reading →

Here is a zip of two examples I built as I’m learning about the new adaptive plans features of Oracle 12c: zip The first example has the optimizer underestimate the number of rows and the adaptive plans feature switches the … Continue reading →

Spent a good amount of time yesterday and today reading about auditing in Oracle 12c.  Can’t say I read every word, but I think it was worth reading the three chapters in the Security manual related to auditing: Chapter 21 … Continue reading →

A RMAN restore and recovery that I completed today answered a couple of questions that remained after the recovery that was the topic of my post from June.  Both today’s recovery and June’s involved a restore of a production database … Continue reading →

This is the second in a series of posts about different performance tuning authors and speakers who have had a big impact on my career.  My first post was on Craig Shallahamer.  I am ordering these posts chronologically.  Craig was … Continue reading →

In an earlier blog post I showed how I used coe_xfr_sql_profile.sql from the sqlt toolkit from Oracle support to force a particular sql statement to run with a more efficient plan that it had used in the past. Today, I’m … Continue reading →

I attended two events this week that used the term “analytics” to describe a performance tuning feature that displays metrics in various useful ways. On Tuesday, I attended a Delphix 4.0 Webinar where Delphix’s CTO Adam Leventhal described the new … Continue reading →

I decided to read the entire Oracle 12c Concepts manual.  It’s kind of overkill to read the entire manual if you just want to learn the new 12c features but it has been a long time since I’ve read the … Continue reading →

Here is the sqlplus scripting I use to check whether row chaining is degrading a query’s performance: VARIABLE monitored_sid number; begin SELECT sid into :monitored_sid from v$session where audsid=USERENV(‘SESSIONID’); end; / select b.value “table fetch continued rows” from V$SESSTAT b … Continue reading →