How Does An Execution Plan Suddenly Change When The Statistics (And Everything Else) Remains The Same ? (In Limbo)

Originally posted on Richard Foote's Oracle Blog:
I’ve slipped this post in as there have been a number of discussions recently on how execution plans have changed while nothing else appears to have changed in the database. How can an execution plan suddenly change when no one has made any changes to the database ?   By no changes, it means that there have been… Continue reading How Does An Execution Plan Suddenly Change When The Statistics (And Everything Else) Remains The Same ? (In Limbo)