PERFORMANCE BAD WHEN CURSORS ARE USED WITHIN PL/SQL BLOCKS
There are poor database performance at Oracle 10g
For some cursor selects, the performance is under Oracle 10g
significant slower than under Oracle 9i.On a test system (Oracle 9) the
problem does not reproduce, on the 10g system however always.
The simple execution of the base select statement was on both
databases in roughly of the same speed. If however a cursor was defined and
those executed within a PL/SQL block (without involving the user interface),
then the time behavior was in accordance with the observed behavior
behavior on the user interface.
By adding of the hint first_rows on both machines a
similar (fast) time behavior can be achieved.
Conclusion: Something in the (Optimizer) settings of the Oracle-10
databases must be fundamentally different than that of Oracle 9. Or Oracle
10 has a real problem. The analysis and solution of this general
problem seems to me more reasonable than the solution of individual performance
problems.
can you help me, many thanks