MySQL Source Installs for each RDS version

I have been doing a lot of Oracle and PeopleSoft work this year, but I am trying to continue to develop my MySQL and Amazon Web Services (AWS) knowledge at the same time. My goal is to learn some new thing about MySQL and AWS each month and then document it either on this blog or on my company’s internal web site.

This month I decided to focus on building a Linux virtual machine on (more...)

Tried Live SQL

Quick post. I tried for the first time.

Looks like you can try out the latest version of Oracle for free. You can type in SQL statements in your web browser.

There seem to be a boatload of scripts and tutorials to try out. Might be good for someone who is new to SQL.


Installed 19.3 on Linux on VirtualBox

I noticed that Oracle database 19.3 was available to download so I installed it on a Linux VM under VirtualBox.

I cloned my base Oracle Linux 7 VM and did a yum -y update to get it up to the latest Linux version.

I installed the preinstall RPM:

yum install oracle-database-preinstall-19c

Created the Oracle home, set some variables, and disabled the firewall.

mkdir -p /home/oracle/product/db/19.0.0
chgrp oinstall /home/oracle/product/db/19.0.0
cd /home/oracle/product/db/19. (more...)

May 17th AZORA Meetup – Last until September!

Example of coe_xfr_sql_profile force_match TRUE

Monday, I used the coe_xfr_sql_profile.sql script from Oracle Support’s SQLT scripts to resolve a performance issue. I had to set the parameter force_match to TRUE so that the SQL Profile I created would apply to all SQL statements with the same FORCE_MATCHING_SIGNATURE value.

I just finished going off the on-call rotation at 8 am Monday and around 4 pm on Monday a coworker came up to me with a performance problem. A PeopleSoft Financials (more...)

Check your hints carefully

Back in 2017 I wrote about how I had to disable the result cache after upgrading a database to This week I found one of our top queries and it looked like removing the result cache hints made it run 10 times faster. But this did not make sense because I disabled the result cache. Then I examined the hints closer. They looked like this:


There should (more...)

Huge Pages Speeds Startup of Web Servers

We had issues deploying changes to a large web farm a few weeks back. We had automated the startup of the 25 web servers using a DevOps tool but when it tried to bring them all up at once it took forever and the web servers got timeout errors. We resolved this by putting in huge pages on the metadata database.

I mentioned the unexpectedly large impact of huge pages on login time in a (more...)

High Processes Cause Semaphore Errors

I could not create a new Delphix virtual database because I kept getting semaphore limit errors. I ended up reducing the processes parameter value to resolve the issue.

I got these errors creating the new VDB:

ERROR : SQL> ORA-27154: post/wait create failed 
ERROR : ORA-27300: OS system dependent operation:semget failed with status: 28
ERROR : ORA-27301: OS failure message: No space left on device
ERROR : ORA-27302: failure occurred at: sskgpcreates

The processes variable (more...)

Python Practice Produced Pretty Pictures

I wrote a Python program that made some fun pictures so I thought I would share them even though this is not really a database post.

I practice Python programming by doing Rosetta Code programming tasks that no one has implemented in Python. This is a fun way of keeping up my Python skills. My most recent contribution made pretty pictures so I thought I would show them here. The code takes a cube and (more...)

Speed of Light

Looking at cloud databases has me thinking about the speed of light. Wikipedia says that the speed of light is about 186,000 miles per second. If my calculations are correct that is 5.37 microseconds per mile. The United States is about 2680 miles wide so it would take light about 14.4 milliseconds to cross the US. If I ping one of my favorite web sites it takes tens of milliseconds to ping so (more...)