在11gR2中,PARALLEL_MAX_SERVERS的值以PROCESSES-15为上限。 在12c中,PARALLEL_MAX_SERVERS的值由PROCESSES - N来限定,其中N是一个内部计算的结果,该计算估计了需要为特定数据库保留的最大背景进程的数量。 例如,使用15的值,如11gR2中: parallel_threads_per_cpu = 2 cpu_count = 4 pga_aggregate_target = ...
SQL> show parameter cpu NAME TYPE VALUE --- --- --- cpu_count integer 8 parallel_threads_per_cpu integer 2 resource_manager_cpu_allocation integer 8 SQL> set timing on SQL> set time on; 15:50:01 SQL> 15:50:02 SQL> show parameter job NAME TYPE VALUE --- --- ---...
cpu_count integer 8 parallel_threads_per_cpu integer 2 resource_manager_cpu_allocation integer 8 SQL> set timing on SQL> set time on; 15:50:01 SQL> 15:50:02 SQL> show parameter job NAME TYPE VALUE --- --- --- job_queue_processes integer 1000 15:50:09 SQL> select bytes/1024/102...
cpu_count integer 8 parallel_threads_per_cpu integer 2 resource_manager_cpu_allocation integer 8 SQL> set timing on SQL> set time on; 15:50:01 SQL> 15:50:02 SQL> show parameter job NAME TYPE VALUE --- --- --- job_queue_processes integer 1000 15:50:09 SQL> select bytes/1024/102...
首先说明下DOP的计算公式:单实例: DOP = PARALLEL_THREADS_PER_CPU x CPU_COUNT RAC: DOP = PARALLEL_THREADS_PER_CPU x CPU_COUNT x INSTANCE_COUNT SQL> alter session set parallel_degree_policy = auto; Session altered. SQL> alter session set "_px_trace"=all; Session altered. SQL> select ...
该参数值=4 x CPU_COUNT x PARALLEL_THREADS_PER_CPU x ACTIVE_INSTANCES parallel_max_servers 最大的parallel进程,parallel_servers_target select n.name, s.value 2 from v$mystat s, v$statname n 3 where s.statistic# = n.statistic# 4 and n.name like 'Parallel%' ...
l PARALLEL_MAX_SERVERS:默认值为PARALLEL_THREADS_PER_CPU * CPU_COUNT * concurrent_parallel_users * 5。该参数确定一个实例并行执行进程和并行恢复进程的最大数。当需求增加时,Oracle数据库从实例启动时的进程数增加到该参数值。在默认值计算公式中,实例上赋予正在使用的concurrent_parallel_users的值和内存管理设...
This is the CPU configuration for the instance I will use for the test: It’s a virtual machine with 4 cores and the instance is configured to use 2 threads per CPU. With this setup, the default DOP is 8. PARALLEL_DEGREE_POLICY is set to “LIMITED” and PARALLEL_DEGREE_LIMIT is set...
PARALLEL(DEFAULT): The optimizer calculates a degree of parallelism equal to the number of CPUs available on all participating instances times the value of thePARALLEL_THREADS_PER_CPUinitialization parameter. PARALLEL(AUTO): The database computes the degree of parallelism, which can be 1 or greater...
parallel_threads_per_cpu integer 1 demo@PDB1> show parameter cpu_count NAME TYPE VALUE --- --- --- cpu_count integer 8 demo@PDB1> Comment byRajeshwaran Jeyabal (@rajeshwaranj)— September 22, 2022 @7:40 am BST Sep 22,2022|Reply Rajeshwaran, Thanks for the comment. I had avoid...