Initialization Parameters, 122 of 188

OPTIMIZER_INDEX_COST_ADJ

Parameter type:
Integer

Parameter class:
Dynamic. Scope = ALTER SESSION.

Default value:
100

Range of values:
1 to 10000

OPTIMIZER_INDEX_COST_ADJ lets you tune optimizer behavior for access path selection to be more or less index friendly--that is, to make the optimizer more or less prone to selecting an index access path over a full table scan.
The default for this parameter is 100 percent, at which the optimizer evaluates index access paths at the regular cost. Any other value makes the optimizer evaluate the access path at that percentage of the regular cost. For example, a setting of 50 makes the index access path look half as expensive as normal.

Note: The adjustment does not apply to user-defined cost functions for domain indexes.

See Also: Oracle8i Designing and Tuning for Performance for more information on setting this parameter, and on its relationship to "OPTIMIZER_INDEX_CACHING".

Parameter type:	Integer
Parameter class:	Dynamic. Scope = `ALTER` `SESSION.`
Default value:	100
Range of values:	1 to 10000
`OPTIMIZER_INDEX_COST_ADJ` lets you tune optimizer behavior for access path selection to be more or less index friendly--that is, to make the optimizer more or less prone to selecting an index access path over a full table scan. The default for this parameter is 100 percent, at which the optimizer evaluates index access paths at the regular cost. Any other value makes the optimizer evaluate the access path at that percentage of the regular cost. For example, a setting of 50 makes the index access path look half as expensive as normal.
Note: The adjustment does not apply to user-defined cost functions for domain indexes.
See Also: Oracle8i Designing and Tuning for Performance for more information on setting this parameter, and on its relationship to "OPTIMIZER_INDEX_CACHING".