PGA_AGGREGATE_LIMIT


Property Description

Parameter type

Big integer

Syntax

PGA_AGGREGATE_LIMIT = integer [K | M | G]

Default value

By default, PGA_AGGREGATE_LIMIT is set to the greater of 2 GB, 200% of PGA_AGGREGATE_TARGET, and 3 MB times the PROCESSES parameter. It will be set below 200% of PGA_AGGREGATE_TARGET if it is larger than 90% of the physical memory size minus the total SGA size, but not below 100% of PGA_AGGREGATE_TARGET.

Modifiable

ALTER SYSTEM

Range of values

Oracle recommends that you do not set PGA_AGGREGATE_LIMIT below its default value. PGA_AGGREGATE_LIMIT cannot be set below its default value except in a text initialization parameter file (pfile) or binary server parameter file (spfile). If a value of 0 is specified, it means there is no limit to the aggregate PGA memory consumed by the instance.

Basic

No


PGA_AGGREGATE_LIMIT specifies a limit on the aggregate PGA memory consumed by the instance.

There is no difference in behavior between PGA_AGGREGATE_LIMIT being explicitly set or being set to the default.

Actions Taken When PGA_AGGREGATE_LIMIT is Exceeded

Parallel queries will be treated as a unit. First, the sessions that are using the most untunable memory will have their calls aborted. Then, if the total PGA memory usage is still over the limit, the sessions that are using the most untunable memory will be terminated.

SYS processes and background processes other than job queue processes will not be subjected to any of the actions described in this section. Instead, if they are using the most untunable memory, they will periodically write a brief summary of their PGA usage to a trace file.

See Also: