# _PGA_MAX_SIZE 限制单个进程下所有工作区的大小 10gR2 | pga_aggregate_target | _PGA_MAX_SIZE | | --- | --- | | <1GB | 200MB | | 1~4GB | 20%*pga_aggregate_target | | >=4GB | 480MB | 11gR2 | pga_aggregate_target | _PGA_MAX_SIZE | | --- | --- | | >=1GB | 10%*pga_aggregate_target | | <1GB | max(20%*pga_aggregate_target,10m) | # _SMM_MAX_SIZE 限制单个进程下单个工作区的最大大小 * For values of PAT below 512 MB, _SMM_MAX_SIZE is 20% of PGA_AGGREGATE_TARGET. * For PAT values of 512 MB and beyond, _SMM_MAX_SIZE is always 50% of _PGA_MAX_SIZE. * In Oracle9i, _SMM_MAX_SIZE had a limit of 100 MB. Following is an example of a session that had two simultaneously active work areas when the given parameters were in effect: MIN(5%*PGA_AGGREGATE_TARGET,100M) 5%*PGA_AGGREGATE即 _smm_max_size - P_A_T <=500MB _smm_max_size =20%*P_A_T - P_A_T <=1000MB _smm_max_size =100MB - P_A_T <=2560MB _smm_max_size =10%*P_A_T - P_A_T >=2560MB _smm_max_size =262060KB # _SMM_PX_MAX_SIZE 限制并行任务的所有工作区总大小 The setting of _SMM_PX_MAX_SIZE is always 50% of PGA_AGGREGATE_TARGET. There is no limit on_SMM_PX_MAX_SIZE(at least not within the tested range of PGA_AGGREGATE_TARGET of 10 MB to 32 GB). In Oracle9i, _SMM_PX_MAX_SIZE was 30% of PGA_AGGREGATE_TARGET. 30%*PGA_AGGREGATE_TARGET/DOP - DOP<=5 _smm_max_size 生效 - DOP>5 _smm_px_max_size 生效