Oracle tuning as a life-or-death endeavor Oracle Database Tips by Donald BurlesonOctober 29, 2015

 

Chris Lawson, author of the bestselling book "The Art and Science of Oracle Performance Tuning" has an amazing new article titled "When Performance Tuning is a Matter of Life and Death".

 

I've noted that Oracle's intelligent tuning advisors which identify missing indexes and materialized view opportunities give many DBA's an over-simplistic view of the complexities of Oracle tuning.  Lawson points out that many DBA's tend to trivialize Oracle tuning:

"Those not truly experienced in tuning tend to trivialize the process, frequently using trite phrases such as ?add missing indexes? or ?increase buffer cache.?

While Oracle DBA's commonly support database than are a life-or-death critical (Hospitals, laboratory equipment), Chris points out that an aggressive mindset is critical to difficult tuning challenges:

"Here's a tactic I use when I?m faced with an apparently unsolvable performance problem.

 

I imagine that the problem is so critical that people will actually die if I don't resolve the difficulty. I imagine that the lives of people are actually in my hands."

Chris also notes some of the real-world tools that are used when mission critical systems are not performing acceptably:

"Given my new motivation, all limits were off. I considered all kinds of crazy ideas'server changes, init.ora changes, disk changes, etc."

Chris leverages on his years of tuning experiences to relate a real-world example where out-of-the-box thinking solved a critical performance issue.  In his example, Chris uses a novel techniques to perform "anticipatory caching" of data locks that were used in a critical job:

"Since the bottleneck was mostly due to disk i/o, any improvement in disk access would directly affect the problem job. Since we knew the exact Sql, we could pre-run Sql that duplicated the ?real? Sql that would shortly follow. That is, we would pre-cache many of the blocks that would shortly be needed.

Caching would take place within the SAN unit, as well as at the Oracle database cache. The entire performance improvement would take place with absolutely no change to the batch program!"

 

You can always tell a real-world tuning professional from a dilettante, and the Oracle community is lucky to get this practical advice from an experienced Oracle tuning guru.

 

For more on life-or-death Oracle databases, See Dr. Hamm's article:

 

My related notes and References: