FreeLists / oracle-l / RE: Heisenberg and measurement intrusion....

["Robert Freeman" <robertgfreeman@xxxxxxxxx>]

Well, there is the concept of metaphor, and I rather like this one... :-)

Back in the 7.x days, measuring performance by turning on timed_statistics
could have a very negative impact on the system. Thus, employing
instrumentation could be metaphorically related to Heisenberg if the process
of employing that instrumentation (thus observing or measuring) would in
fact alter the database (the electron) such that your measurement was
worthless.

I've seen "instrumentation" packages that people have written that have had
a pretty negative impact on performance (I've seen products with traits like
this too). Also, I've seen the nuclear approach (let's just monitor
everything) to monitoring rather than the strategic approach (let's figure
out where specific problem areas are and instrument them more fully) can
cause performance problems.

Speaking of Metaphors...

That time of year thou mayst in me behold
Where yellow leaves, or none, or few, do hang
Upon those boughs which shake against the cold,
Bare ruined choirs, where once the sweet birds sang.
Shakespeare Sonnet LXXIII, a metaphor for me (either me getting older or
loosing hair, I'm not sure which)... :-)

Cheers!!!

RF
Robert G. Freeman
Oracle Consultant/DBA/Author
Principal Engineer/Team Manager
The Church of Jesus Christ of Latter-Day Saints
Father of Five, Husband of One,
Author of various geeky computer titles
from Osborne/McGraw Hill (Oracle Press)
Oracle Database 11g New Features Now Available for Pre-sales on Amazon.com!
BLOG: http://robertgfreeman.blogspot.com/
Sig V1.2