It occurred to me that it is sometime necessary to drop an UNDO tablespace after creating a new UNDO tablespace and changing our instance to use the new one. It occurred to me that Oracle should not allow you to…
Great whitepaper on connection management in RAC
This is a fantastic whitepaper on workload management in RAC. It is essential reading for anyone supporting a RAC environment, or an architect of a middle tier that wants to understand how connections are handled by the database. http://www.pythian.com/documents/Pythian_RAC_Whitepaper.pdf
Processor architecture
oracle@kcdb01:~> echo “You have $(cat /proc/cpuinfo | grep “physical id” | sort -u | wc -l) $(cat /proc/cpuinfo | grep cores | head -1 | awk ‘{print $4}’) core processors” You have 2 4 core processors oracle@kcdb01:~>
Range scans when using VARCHAR2 instead of NUMBER
I was a little surprised today when another DBA did not know the effect of using a VARCHAR2 datatype for what is functionally a number. I wanted to ensure I had an article to which I could point when this…
Do we actually use characters that require more than one byte?
I couldn’t find a way to identify those columns that actually had a character with a code point value greater than 255. As a result, I ended up writing the following. If you have better way, please reply. import java.sql.*;…
Space used with a multi-byte database characterset
We found our database was using a lot more space than when we issued a select dbms_lob.getlength() on CLOB columns. We found our issue was that our database characterset is AL32UTF8, so everything requires more space. To test this, we…