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What is PGA aggregate target?
PGA_AGGREGATE_TARGET specifies the target aggregate PGA memory available to all server processes attached to the instance. Setting PGA_AGGREGATE_TARGET to a nonzero value has the effect of automatically setting the WORKAREA_SIZE_POLICY parameter to AUTO .
What is the use of PGA in Oracle?
A Program Global Area (PGA) is a memory region that contains data and control information for a server process. It is nonshared memory created by Oracle Database when a server process is started. Access to the PGA is exclusive to the server process. There is one PGA for each server process.
Is PGA aggregate limit dynamic?
and the 2GB is used up, then, no more memory can be used for the PGA, and the ORA-04036 error will be recorded in the alert log. PGA_AGGREGATE_LIMIT = hard limit => no more memory can be allocated. This parameter is dynamic, and it should not be set to a lower value than PGA_AGGREGATE_TARGET parameter.
Is Pga_aggregate_target dynamic?
You can simplify and improve the way PGA memory is allocated by enabling automatic PGA memory management. In this mode, Oracle Database dynamically adjusts the size of the portion of the PGA memory dedicated to work areas, based on an overall PGA memory target explicitly set by the DBA.
How to set a hard limit for aggregate PGA memory?
PGA_AGGREGATE_TARGET specifies the target aggregate PGA memory available to all server processes attached to the instance. For a PDB, the default value is the same as the CDB’s default value. To set a hard limit for aggregate PGA memory, use the PGA_AGGREGATE_LIMIT parameter.
What is the purpose of PGA aggregate target?
The RAM allocated to the PGA_AGGREGATE_TARGET is used by Oracle connections to maintain connection-specific information (e.g., cursor states) and to sort Oracle SQL result sets.
Why is PGA aggregate target used in Oracle9i?
PGA_AGGREGATE_TARGET allows Oracle9i perform far faster than earlier version because the memory is only allocated in used for the duration of the session upon which is immediately freed up to become available for use by other connected Oracle tasks. By default oracle database uses PGA_AGGREGATE_TARGET 20% of SGA Size.
Is there a maximum PGA size for a PDB?
When this parameter is set for a PDB, it specifies the maximum PGA size for the PDB. The NONCDB_COMPATIBLE initialization parameter must be set to FALSE at the CDB level (in the root of the CDB). The MEMORY_TARGET initialization parameter must not be set at the CDB level.