Posts Categorized: Technical Blog

Revealing the Hints Behind the Automatic SQL Tuning Advisor

A client recently supplied a list of 50+ SQL IDs that should receive SQL profiles, and I’ve been working with Gwen Shapira to review the list. Further discussion showed that this list had come from the Automatic SQL Tuning feature, installed by default in Oracle 11g. The report includes a list of recommended SQL profiles ordered by “Maximum Benefit”, and in our case it included several hundred statements. The expected workflow, as far as I can gather, is to see the recommendations, look at the before- and after- execution plans, and accept the recommendations. Before blindly accepting recommendations, though, I like to see what exact changes are being proposed. They aren’t listed anywhere in the report, and require some extra work to uncover. The first step is to get the automatic SQL tuning advisor report. (

Temporary Tablespaces: to BIGFILE or Not to BIGFILE

The environment was an Exadata environment undergoing pre-production stress testing. We used Real Application Testing to take a highly-concurrent OLTP workload, and replayed the workload with the synchronization parameter set to FALSE, effectively increasing concurrency beyond the original test system. AWR showed a large volume of buffer busy activity.

Character Set Conversion 10g and 11g – Part 1

This post is the first in a series of discussions … perhaps you have never had the pleasure of needing to change a character set. If you have not and soon do, purchase a good sleeping bag as you may be at the office late for a few days to get the task accomplished.

MySQL Oracle Connect 2012: Day Two

Another interesting day today, I was attending the keynotes and I have found them quite interesting. Specially the way Tweeter use MySQL to build-up a nosql solution, jokes a side I take few notes on things I must analyze and dig in. Interesting one was also the introduction of the Paypal models, which brings me to attend the presentation later on. Presentation was well constructed and with some good theoretical work, but I was quite disappointed, I found the presentation incomplete, and missing real numbers for the MySQL Cluster NDB setup.

Exadata X3H2M2: A Few Thoughts

Tonight at Oracle OpenWorld, Oracle CEO Larry Ellison announced the latest Exadata release: X3. It sports a hardware refresh including a big expansion in RAM and flash storage capacity: 4TB and 22TB respectively on a full rack. Read my thoughts on this here.

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