Thanks to everyone who attended my webinar sponsored by Red Gate and All Things Oracle. My topic was "How to Gather SQL Resource Consumption Metrics in Oracle". The webinar recording has been posted at AllThingsOracle as of May 9 but I thought I'd also make the materials available here for anyone interested. In the zip file, you'll find a PDF of the presentation slides, several example reports (ASH, AWR, SQL Monitor) as well as several scripts I used and a text file containing all the demo queries and output.
These are my personal rules that I’ve been following moderating the public forums on LinkedIn. I’ve posted on that topic in the discussion on IOUG Exadata SIG forum. As I’m passing RAC SIG group to the next folks on the board (I’m the RAC SIG president until end of August) I needed to hand over...
At ODTUG Kaleidoscope 2012, there will be a Database Experts Panel Q&A session on Monday afternoon, 25 June at 4:15pm. The panel is 100% Oakies, so please stop by if you're attending the conference. Of course, the good people at ODTUG have placed the session in the Grand Oaks D/C room.
Here's the session's abstract from the conference program:
This session provides an open Q&A for attendees to pose questions about Oracle Database and Oracle Exadata to a panel of OakTable database experts: Cary Millsap, Maria Colgan, Jonathan Lewis, Dominic Delmolino, Tim Gorman, and Dan Norris. Maximum time will be devoted to answering questions from the audience, so be sure to bring your questions and prepare for some great discussions!
Back in the (really) old days, systemstate dumps had to be used for diagnosing hangs and finding blockers of hung databases. Basically you just identified which resource your waiting sessions were waiting for and then scanned through the rest of the system state dump to see which session held that particular resource (note that over time the instrumentation and systemstate dumps have evolved to resolve and dump the blocker information right at the waiting session section in the dump).
Diagnosing complex hangs was a tedious manual process (or required some scripting), so the hanganalyze was a really welcome addition to hang diagnosis. The hanganalyze basically walked through the blocker-waiter chains, found which session was the LEAF in the chain (the LEAF is the ultimate/final blocker in the wait chain), which everybody either directly or indirectly was waiting for.
Oracle Technology and Business Consulting
Usually I'm pushing information out - now I need to pull some in.
We're evaluating the usage of XMLDB in the database community. We would like to know what components of XMLDB are most frequently used. Please let us know which of the following you use:
In 1990, when Ken Jacobs hosted the RDBMS campground talks at the Anaheim International Oracle User Week appreciation event, one of the topic areas was whether we (some users representing the Very Large DataBases VLDB of the Oracle world which meant anything north of about 7 GB back then) thought that the rule based optimizer (RBO) was good enough, or whether we needed a cost based optimizer (CBO) for the real applications we were running at enterprise scale to work well. “Oracle’s optimizer is like Mary Poppins. It’s practically perfect in every way. But we do have some cases where it would be helpful for the optimizer to consider the relative sizes of tables and whether a table was local or remote when the plan for joining and filtering is constructed.
Having mentioned a couple of dangers associated with IOT Secondary Indexes, thought I might discuss a couple of their nicer attributes. In the previous post, we saw how 50-50 index block splits on the ALBUM_SALES_IOT IOT table caused rows to move to new leaf blocks, resulting in a degradation in the PCT_DIRECT_ACCESS value of the associated ALBUM_SALES_IOT_TOTAL_SALES_I secondary [...]