A database statement, such as a SQL text, reuses the execution plan compiled
for
a similar SQL text found in memory if the value of a system parameter is configured
for cursor sharing among optimally shareable SQL texts and the SQL text is optimally
shareable with the similar SQL text found in memory. Reuse also occurs if the value
of a system parameter is configured for cursor sharing among all shareable SQL
texts and the SQL text is suboptimally or optimally shareable with the similar
SQL text found in memory. For SQL text that is non-shareable with a similar SQL
text found in memory, no execution plan sharing takes place.