Friday, April 14, 2006
Mr. Jonathan Lewis's article "When 2+2=5"
"From web page of Jonathan Lewis comes his debunking of the myth (Urban legend?) that using the predicate of 1=2 causes a full table scan. On the page When 2 +2=5 Mr. Lewis goes through in detail his tests to prove this myth wrong. This is simply a continuation of his tests on versions 7 through 10xe of oracle to validate or invalidate his conclusions as Mr. Lewis does state this is the same on many versions of oracle but doesn’t provide proof. I did this because a colleague of mine disagreed with Mr. Lewis’s findings and just “knew” that Mr. Lewis was wrong and I had some time at home to kill. I will not draw any conclusions, or make any statements. I have simply provided the complete result sets and let you come to your own conclusions. All of these tests were done in production databases that were busy doing other work at the time, I thought this an appropriate environment instead of a sterile environment. I have provided the output from V$VERSION in every log. The entire output is here I moved the post to a file on my googlepages site as the post was massive and difficult to read. Draw your own conclusions based on the information supplied above.