Category Archives: Uncategorized

I just wanted to double check something on my Exadata slides.  I think I had checked this before but became unsure if something I was saying was true, namely that when you run a normal non-smart scan query on Exadata … Continue reading →

I ran into a case today where I had tuned a query by putting a cardinality hint into a view, but the optimizer changed the plan anyway by overriding the cardinality hint with cardinality feedback.  So, I found out how … Continue reading →

Whenever I need to test a query that has bind variables I usually go to the development team to ask them what typical values are or what the values were the last time the query ran.  I’m pretty sure that … Continue reading →

Here is a link to my updated Exadata PowerPoint presentation. I’ve been trying to improve my Exadata talk for the Collaborate 13 conference.  I’ve done this talk at work and at the ECO conference in October but I’m not completely … Continue reading →

I spent a lot of time yesterday digging into performance issues on a new database only to find a simple issue where two tables were joined on a column that was a number on one table and a varchar2 on … Continue reading →

OK.  This is really cool.  I found an archive of my old geocities blog: archive I thought geocities was gone forever but it isn’t.  Quite cool. – Bobby

I don’t focus on the Oracle optimizer’s cost of a particular execution plan when I’m tuning a query and I’m worried that many of the developers and DBAs that I’ve talked with about query tuning are too focused on lowering … Continue reading →

My company is trying out a new product called Delphix. We have had Delphix installed for about a month and I wanted this post to contain my first impressions for others who may be considering it.  Essentially Delphix provides fast … Continue reading →

My Exadata talk got accepted by the IOUG and the deadline for the slides and paper is rapidly approaching.  I’ve had the slides for a while but have never written the presentation down as a paper before.  So, I’ve posted … Continue reading →

We have event 27401 level 16384 set on some of our systems and it appears that this is preventing the scheduler from changing the active resource manager plan when the window opens. I haven’t been able to find any documentation … Continue reading →