ba6.us - Dave's Database Related Stuff

I recently had an issue where a query being submitted to the database had a large change in performance. I could attribute the change to a recent change in object statistics, but the query wasn't behaving because of a combination of a view, subquery, UNION, and LIKE operators. After spending too much time on this statement I decided to hint it to make it perform like it did before the most recent stats change. Read more »

I ran across Orion in a Kevin Closson blog post. From the OTN site:

"ORION (Oracle I/O Calibration Tool) is a standalone tool for calibrating the I/O performance for storage systems that are intended to be used for Oracle databases. The calibration results are useful for understanding the performance capabilities of a storage system, either to uncover issues that would impact the performance of an Oracle database or to size a new database installation. Since ORION is a standalone tool, the user is not required to create and run an Oracle database. " Read more »

Its time to test some IO.

I have used OraBM/OraStress in the past to throw a load at an Oracle server.

This time I wanted to see what else was out there. I had seen mention of HammerOra on forums and listserves so I figured I'de give it a shot. Here's what it took to get it running on a Windows server.

1) Download and Install HammerOra

Their home page is here: http://hammerora.sourceforge.net/ Read more »

If you haven't seen this optimizermagic.blogspot.com post already, check it out.

It covers the standard Execution Plan stuff, but also covers use of the dbms_xplan package including using dbms_xplan.display to format output and using dbms_xplan.display_cursor to see Bind Variables used to generate a plan!

Click here for Article

-- Dave

I haven't look at Oracle's Remote Diagnostic Agent (RDA) tool in a couple of years. Back when we ran our systems on Windows I remember using a clunky version of RDA that looked like it was cobbled together with batch files and VB code.

What is RDA? From the Oracle website: Read more »