Execution plans

Jonathan Lewis's picture

double trouble

In the latest Quiz Night, I asked how you could make a query more efficient by changing a two table join into a three table join – with the clue that my third table was a repeat of the first table. Gary Myers, in comment 4,  provided the type of answer I was looking for. Sometimes [...]

Jonathan Lewis's picture

10053 viewer

I’ve been trying to find a way to post an executable for several weeks because I’ve been sent a simple viewer for 10053 trace files written by Hans-Peter Sloot of Atos Origin and Robert van der Ende. They wrote this viewer because trace files from event 10053 can be enormous, and scrolling back and fore [...]

Jonathan Lewis's picture

Rule Rules

Everybody knows you shouldn’t be using the Rule-based optimizer (RBO) any more – everyone, that is, except some of the folks at Oracle Corp. I had a conversation a few weeks ago with someone who was having a problem with their standby database on 10.2 because a query against v$archive_gap was taking a very long [...]

Jonathan Lewis's picture

Analyze This – 2

If you’ve run the scripts from Analyze This, I hope you found that the query gave you two different execution plans. This is my output from the test (with a little cosmetic tidying):

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Using Analyze
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Execution Plan
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Plan hash value: 1838229974

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| Id | Operation | Name | [...]

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