Author Archives: Bobby

About Bobby

I live in Chandler, Arizona with my wife and three daughters. I work for US Foods, the second largest food distribution company in the United States. I have worked in the Information Technology field since 1989. I have a passion for Oracle database performance tuning because I enjoy challenging technical problems that require an understanding of computer science. I enjoy communicating with people about my work.

Memory added based on buffer pool advisory did not give desired result

Development asked me to look at ways to cut the run time of a series of PeopleSoft payroll batch jobs so I took an AWR report of the entire 4 hour period.  Based on the waits, the percentage of the elapsed time … Continue reading

Posted in Uncategorized | 2 Comments

Script to get previous month’s AWR report

We keep 6 weeks of history in the AWR on our databases, but I want to capture some information for long-term trending. What I really want to do is capture some metrics and put them in some database tables to … Continue reading

Posted in Uncategorized | Leave a comment

Applied July Patch Sets To Test Databases

I applied the current July patch sets to a 11.2 and a 12.1 test database.  Now I have a 11.2.0.4.7 and a 12.1.0.2.4 test database.  It is helpful to have test databases that are on the most current patch sets and … Continue reading

Posted in Uncategorized | Leave a comment

Registered for Oracle OpenWorld

I registered myself for Oracle OpenWorld and I have my hotel reserved and my flights ticketed. I think it has been over 12 years – probably more like 15 years – since I went to OpenWorld. I went at least once … Continue reading

Posted in Uncategorized | Leave a comment

Check out 6.00.1x computer science class on edX!

I just finished the last program for a computer science class on edX and I urge you to try it. I took this class: MITx: 6.00.1x Introduction to Computer Science and Programming Using Python I was more interested in how MIT taught the class than … Continue reading

Posted in Uncategorized | 5 Comments

Flushing Shared Pool Does Not Slow Its Growth

I’m still working on resolving the issues caused by bug 13914613. Oracle support recommended that we apply a parameter change to resolve the issue but that change requires us to bounce the database  and I was looking for a resolution … Continue reading

Posted in Uncategorized | 2 Comments

Overall I/O Query

I hacked together a query today that shows the overall I/O performance that a database is experiencing. The output looks like this: End snapshot time number of IOs ave IO time (ms) ave IO size (bytes) ——————- ————- —————- ——————- … Continue reading

Posted in Uncategorized | 14 Comments

Bug 13914613 Example Shared Pool Latch Waits

Oracle support says we have hit bug 13914613.  Here is what our wait events looked like in an AWR report: Top 5 Timed Foreground Events Event Waits Time(s) Avg wait (ms) % DB time Wait Class latch: shared pool 3,497 17,482 … Continue reading

Posted in Uncategorized | 1 Comment

Surprising calibrate_io result

Recently I used DBMS_RESOURCE_MANAGER.calibrate_io to measure disk I/O performance using a call like this: DECLARE l_latency PLS_INTEGER; l_iops PLS_INTEGER; l_mbps PLS_INTEGER; BEGIN DBMS_RESOURCE_MANAGER.calibrate_io (num_physical_disks => 10, max_latency => 20, max_iops => l_iops, max_mbps => l_mbps, actual_latency => l_latency); DBMS_OUTPUT.put_line(‘Max IOPS = ‘ … Continue reading

Posted in Uncategorized | 3 Comments

Free MIT Computer Science Classes Online

This is very cool: There are a bunch of nice computer science classes online from MIT: Free online MIT computer science classes Here is an introductory computer science class: Intro to computer science Here is a graded version of the same … Continue reading

Posted in Uncategorized | 3 Comments