Welcome to the 28th edition of Log Buffer, the weekly review of database blogs. It was a busy week in the blogs, but then, it always is.
For several years, I worked as an Oracle Consulting employee, and I’d like to share my experience in that role, working on a massive Oracle Applications implementation deployed in an FDA-regulated company.
If you have found rman backups slow in Oracle 10.2.0.2, you should check out note 375386.1 on metalink. It seems the CBO isn’t all its made out to be, and you have to force rman to use the RULE hint instead to make your rman backup run faster
Not that I participate there often but couple months ago I pulled out my 7 years old account there and wanted to change its password. To my surprise – I’m not able to do it.
In one of my previous posts I mentioned SYSTEM_PRIVILEGE_MAP view. Taking this thread further, I looked into another nice view – V$ENABLEDPRIVS – showing the privileges enabled for the session at the moment. It should be pretty useful if you decide to add some diagnostics into your application. You might also find it very helpful to call from PL/SQL.
We humans are not able to process large amount of precise data. In any human–readable report, we don’t need more than ten or twenty lines of numbers. Every time we look at processes or data more complex that that, we employ simplifications — graph trends, mind–mapping, aggregations, and so on. How will we make computers process information just as humans do? Perhaps we can find the answer inside ourselves if we figure out how our minds work. We recognize images even though our brain is not capable of processing huge amounts of data in milliseconds.
MySQL – No Index Used With ORDER BY + LIMIT and DISTINCT. This is actually a follow up on my previous post. Developers tried to rewrite all statements and even overdid it. As we say in Russia – “teach fool how to pray and he will break his forehead”.
Doug Burns posted photos with his new teammates on his blog, and I felt they deserved a mention here too.
Robert Treat has published the 27th edition of Log Buffer, the weekly review of database blogs, on zillablog.
Filesorts and temp tables are a necessary evil in MySQL, used when MySQL must sort the data before returning the output to the user. They are the most common issue with slow queries in MySQL, the main reason being that if the output is too large, you can kiss goodbye in-memory performance, and say hello to disk access.