1. Database Reference
  2. Initialization Parameters
  3. Initialization Parameters
  4. OPTIMIZER_ADAPTIVE_PLANS

1.212 OPTIMIZER_ADAPTIVE_PLANS

OPTIMIZER_ADAPTIVE_PLANS controls adaptive plans. Adaptive plans are execution plans built with alternative choices that are decided at run time based on statistics collected as the query executes.
Property Description

Parameter type

Boolean

Default value

true

Modifiable

ALTER SESSION, ALTER SYSTEM

Modifiable in a PDB

Yes

Range of values

true | false

Basic

No

Oracle RAC

The same value must be set on all instances

Setting this parameter to false disables the following adaptive features:

  • Nested loop join/hash join selection

  • Star transformation bitmap pruning

  • Adaptive parallel distribution method

Note:

This initialization parameter is available starting with Oracle Database 12c Release 2 (12.2.0.1).

See Also:

Oracle Database SQL Tuning Guide for information about adaptive plans