Setting the cursor_sharing to either similar or force allows similar statements to share SQL area.
The difference between similar and force is that similar forces similar statements to share SQL area without deteriorating execution plans.
Setting cursor_sharing to force forces similar statements to share the executable SQL area, potentially deteriorating execution plans. Hence, force should be used as a last resort, when the risk of suboptional plans is outweighting by the improvements in cursor sharing.
==>deteriorating=changing
