被引用地址:http://blog.csdn.net/changyanmanman/article/details/7991768
在Oracle 10g中,log_parallelism参数变为隐含参数,并且Oracle引入了另外两个参数,允许log_parallelism进行动态调整。
缺省的_log_parallelism_dynamic参数被设置为True,如果_log_parallelism_max被设置为不同于_log_parallelism的参数值,那么Oracle会动态的选择并行度,当然不超过最大允许值,这是Oracle10g中动态SGA的另外一个提高。
SQL> @d:\script\gethiddenpar Enter value for par: log_parallelism old 14: x.ksppinm like '%_&par%' new 14: x.ksppinm like '%_log_parallelism%' NAME VALUE ISDEFAULT ISMOD ISADJ ---------- ------------- --------- ---------- ---- _log_parallelism 1 TRUE FALSE FALSE _log_parallelism_dynamic TRUE TRUE FALSE FALSE _log_parallelism_max 1 TRUE FALSE FALSE SQL> select * from v$version; BANNER ---------------------------------------------------------------- Oracle Database 10g Enterprise Edition Release 10.1.0.3.0 - Prod PL/SQL Release 10.1.0.3.0 - Production CORE 10.1.0.3.0 Production TNS for 32-bit Windows: Version 10.1.0.3.0 - Production NLSRTL Version 10.1.0.3.0 - Production |
获得隐含参数的脚本,请参考:http://blog.csdn.net/changyanmanman/article/details/7899039
并行度显然和CPU数量有关,
SYS AS SYSDBA on 15-MAR-05 >show parameter cpu_count NAME TYPE VALUE ------------- --------------- -------- cpu_count integer 4 SYS AS SYSDBA on 15-MAR-05 >@gethiddenpar Enter value for par: log_par old 14: x.ksppinm like '%_&par%' new 14: x.ksppinm like '%_log_par%' NAME VALUE ISDEFAULT ISMOD ISADJ ------ ---------------- --------- ---------- ----- _log_parallelism 1 TRUE FALSE FALSE _log_parallelism_dynamic TRUE TRUE FALSE FALSE _log_parallelism_max 2 TRUE FALSE FALSE |