We recently migrated from 8.0.5 and 8.1.7 and found out some of the
execution plans have changed.
The statistics were computed right after the database was created. I tuned
some queries and saved the new plans.
Today I discovered that some of those plans have changed, which led to a
performance degradation.
Statistics were unchanged since that first gathering.
So I computed stats again and this returned me to the original plans. Now I
don't want this situation to reoccur but the question remains: what forced
Oracle to change execution plans with the stats unchanged?
Thanks in advance,
Ilya.
Received on Mon Jul 29 2002 - 18:16:32 CDT
