Rule-based optimizer.

"While knowing the rules is helpful, they alone do not tell
you enough about how to tune for the rule-
based optimizer."

"However, more headaches were to come. The same index was the
ideal candidate for the following
statement, which was one of the statements run frequently during
end-of-month and end-of-year
processing"

"Inserting 256 rows with 0 indexes
.101 seconds
Inserting 512 rows with 0 indexes
.161 seconds
Inserting 256 rows with 5 indexes
3.936 seconds
Inserting 512 rows with 5 indexes
2.788 seconds
Inserting 256 rows with 10 indexes
2.558 seconds
Inserting 512 rows with 10 indexes
22.132 seconds "

"Cursor sharing does not work for outlines. I am sure that
Oracle will address this issue in
the future. "