Do like Kirk did
How did James Tiberius Kirk
beat the Kobayashi Maru
? He changed the rules. As performance analysts, to beat the performance game Oracle sometimes allows us to change the rules as well. While relational heresy to some, the commit write
facility is an in your face
way to improve redo constained performance.
In a nutshell, the commit write facility is this: When a commit is issued and the client process quickly receives a "commit complete", it's not really completed... not yet anyway. So there is a possibility of loosing committed data.
This is an unusual post because it's rare my work is published by traditional media. The magazine DB Trends and Applications
(DBTA) published an article I wrote entitled, Uniting Operations Research With Time-Based DB Performance Analysis
. If you receive the printed magazine it's on page 28 of the December 2011 issue but you can also read it on-line here
What's the article about? In the short article, I introduce
Unit of Work Time Based Analysis as the intersection of Oracle performance firefighting and Oracle forecasting and predictive analysis.
This intersection is one of the main themes in my two (more...)
Cache buffer chain (CBC) latch contention is a common top Oracle wait event. There are a number of interrelated causes but also a number of solutions. The trick is to properly diagnose the problem which results in a short list of solutions.
The CBCs are created as a hashing structure and are primarily used to determine if a block currently resides in the buffer cache. (More->>
) As you can image, even the smallest Oracle systems ask, "Is a block in the buffer cache?" a ga-zillion times each day. If CBC access continues to intensify, at some point (more...)