Oracle/ColdFusion/bind variables

[mike_d]

Folks,

I’m trying to resolve the performance issue related to ColdFusion and dynamic list of variables in IN-list clause for various SQL statements. ColdFusion is not very good with bind variables and after several attempts developers made a decision not to use them. As a result, database is flooded with a bunch of similar SQL statements with the only difference in IN clause. The result – high latch waits/contention and poor overall performance. The solution – get back to bind variables. Do you know what be the best approach to it? Unfortunately, I don’t have a lot of experience in this area.

Your help will be greatly appreciated.

Thanks a lot.

Mike Darevsky

[denevge]

maybe this can help you


CURSOR_SHARING
Parameter type String

Syntax CURSOR_SHARING = {SIMILAR | EXACT | FORCE}

Default value EXACT

Parameter class Dynamic: ALTER SESSION, ALTER SYSTEM




CURSOR_SHARING determines what kind of SQL statements can share the same cursors.

Values:

FORCE

Forces statements that may differ in some literals, but are otherwise identical, to share a cursor, unless the literals affect the meaning of the statement.

SIMILAR

Causes statements that may differ in some literals, but are otherwise identical, to share a cursor, unless the literals affect either the meaning of the statement or the degree to which the plan is optimized.

EXACT

Only allows statements with identical text to share the same cursor.


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Note:
Forcing cursor sharing among similar (but not identical) statements can have unexpected results in some DSS applications, or applications that use stored outlines.

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See Also:
Oracle9i Database Performance Guide and Reference for information on setting this parameter in these and other environments