Changes in explain plan and real execution plan depends on the env
differences between the sessions in which you are explain planning
and the one in which you are executing the statement. Sometimes app
changes session level parameters at login time which can change
execution plan.
Regards,
Vishal Gupta
On 16 Nov 2009, at 23:28, "Lei Zeng" <lzeng@xxxxxxxxxxxxx> wrote:
Hi, all:
I have a question about the explain plan.
Under what conditions, could the plan I get out of ‘explain
plan’ differ from what I get from running the sql statement?
Suppose the database has no change during I ran ‘explain plan’
and run the sql – I mean, no ddl and dml – You would think this
database is static. Or the time gap between I run ‘explain plan’
and run sql statement is too narrow to allow any change (ideal env
ironment). No bind variable peeking because _optim_peek_user_binds
is set to FALSE.
Any idea? Thanks in advance.
Lei
