Oracle adjusting pga_aggregate_target Oracle Tips by Burleson Consulting

Adjusting pga_aggregate_target

The DBA may wish to consider dynamically changing the pga_aggregate_target parameter when any one of the following conditions are true:

§       Whenever the value of the v$sysstat   statistic “estimated PGA   memory for one-pass” exceeds pga_aggregate_target  , the pga_aggregate_target should be increased.

§       Whenever the value of the v$sysstat   statistic “workarea executions – multipass” is greater than 1 percent, the database may benefit from additional RAM memory.

§       It is possible to over-allocate PGA memory, and the DBA might want to consider reducing the value of pga_aggregate_target  whenever the value of the v$sysstat row “workarea executions—optimal” consistently measures 100 percent.

Also, see my other notes on adjusting the pga_aggregate_target:

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