I am finally able to announce when and where the Pythian BoF session has been scheduled! It will be in the Alameda room, 7:30-8:30pm on Tuesday, April 15th. The session, titled “Ask the Pythian Maestro”, will be attended by myself and our two MySQL team leads, Sheeri K. Cabral and Augusto Bott.
If you can’t attend the MySQL Conference, you can still virtually attend. 2-3 pm PDT on Tuesday, April 15th for the “Best Practices for Database Administrators” session, and, 11:55 am -12:40 pm PDT on Thursday, April 17th for the “Database Security Using White-Hat Google Hacking” session. You need nothing but your web browser; unlike some other live meetings, audio streams from the website too, so there’s no phone number to call or participant code or anything. There’s also a live chat so you can participate and ask questions while the session is going on.
Welcome, readers, to the 92nd Log Buffer, the weekly review of database blogs.
There’s no video for Jacob Nikom’s December 2007 Boston MySQL User Group meeting, but the slides for “Measuring MySQL Server Performance” can be downloaded here.
We all have encountered this situation many times before: the cost-based optimizer assumes no correlation between two columns (until 11g), and this has the effect of erroneously reducing the cardinality of a row source. Incorrect cardinality estimates are one of many root causes for SQL performance issues. Consider the following example.
After setting up dg4odbc to connect to a SQL Server database (read ‘Tips on Using dg4odbc on 64-bit Linux’), I spent last week trying to get refreshes of materialized views to work in 11g, using the same DDL as in 8i. So, to those three tips, I now add #4: check the statements that use a WHERE … IS NOT NULL across the remote database link to ANSI-compliant databases.
Since the introduction of ASM in Oracle 10g Release 1, every ASM administrator has been dreaming of a simple command line tool to copy files between ASM diskgroups and other filesystems. Oracle ASM 10g Release 2 added the handy asmcmd utility, but even though everyone expected a copy command there, it had not been implemented. While working on a Collaborate 08 presentation on Oracle 11g new features out-of-the-box, I was verifying new commands in Oracle ASM 11g’s asmcmd utility. It turned our that copying files from or to ASM is still a problem.
Ever wished the listener.log file was a table in the database? Wish no more! About three years ago, I sent this recipe in an email to my co-workers. Just recently, Shakir re-sent it after using the method in an emergency. Since it seems to have proved its value, I now offer it to our readers. Have a look.
Over-the-Top Tales from the Trenches: Bringing order to the chaos of every day DBA life – So you have got your nice MySQL Master-Slave replication pair setup. Everything is sweet, then the master dies/restarts or you have a slightly extended network outage. You log into the machine and check out why the slave threw an error or if your monitoring is slow, why the slave is lagging by 2 hours. You run SHOW SLAVE STATUS\G
I recently installed Oracle DB 10.2.0.1 RAC (two nodes) on Oracle Enterprise Linux x86_64 and faced three issues. Since I had to dig out at several places, I thought it might benefit others to have my notes all here.