WORKAREA_SIZE_POLICY与自动PGA内…

文档地址：http://docs.oracle.com/cd/B19306_01/server.102/b14237/initparams227.htm#REFRN10231

 

WORKAREA_SIZE_POLICY

 

Property	Description
Parametertype	String
Syntax	WORKAREA_SIZE_POLICY = { AUTO | MANUAL }
Defaultvalue	AUTO
Modifiable	ALTERSESSION, ALTER SYSTEM

WORKAREA_SIZE_POLICY specifies the policy forsizing work areas. This parameter controls the mode in whichworking areas are tuned.--设置这个参数WORKAREA_SIZE_POLICY为auto,manual的操作既可以在会话级别上完成，也可以在实例级别上完成。

Values:

• AUTO

  Work areas used by memory-intensive operators are sizedautomatically, based on the PGA memory used by the system, thetarget PGA memory set in PGA_AGGREGATE_TARGET, and therequirement of each individual operator.

• MANUAL

  The sizing of work areas is manual and based on the values ofthe *_AREA_SIZE parameter corresponding to theoperation (for example, a sort uses SORT_AREA_SIZE).Specifying MANUAL may result in sub-optimalperformance and poor PGA memory utilization.