首页 > 数据库 > Oracle > Oracle 19C 数据库参数推荐(三)
| 参数名 | 19c默认值 | 标准参考值 | 参数相关参考文档 | COMMAND |
| pga_aggregate_limit | 2147483648 | NON-CDB 0
CDB 默认值 |
所有session PGA总和的硬限制,建议设置成0,取消硬限制 | alter system set pga_aggregate_limit=0 scope=spfile sid='*'; |
| pga_aggregate_target | 639631360 | 起始值设置为物理内存10%
按需设置 |
控制PGA组件内存大小,由应用系统决定,建议不小于1G,起始值设置为物理内存10% | alter system set pga_aggregate_target=0 scope=spfile sid='*'; |
| resource_manager_plan |
|
NON-CDB默认值
CDB:DEFAULT_CDB_PLAN |
To enforce CPU resource allocations, you must set RESOURCE_MANAGER_PLAN to "DEFAULT_CDB_PLAN" at the CDB level. DEFAULT_CDB_PLAN implements the following functionality:
(1) The PDB's CPU usage is limited to the PDB's CPU_COUNT, starting in 12.2. (2) The shares (relative importance) of each PDB for CPU scheduling is set, based on the PDB's CPU_COUNT, starting in 18.1. How to Provision PDBs, based on CPU_COUNT (Doc ID 2326708.1) |
alter system set resource_manager_plan=DEFAULT_CDB_PLAN scope=spfile sid='*'; |
| result_cache_max_size | 9666560 | 0 | 推荐值为0,取消result cache功能 | alter system set result_cache_max_size=0 scope=spfile sid='*'; |
| sga_max_size | 1929379840 | 起始值设置为物理内存40%,同时设置SGA各组件大小
按需设置 |
控制SGA组件内存的最大值,一般设置为与sga_target参数相等, 如果有特殊考虑,比如考虑到后期可能的分区内存动态增加,需要动态增大sga_target的话,可以考虑把SGA_MAX_SIZE相应设置大一些(如果设置>=100G,建议设置 _ksmg_granule_size=134217728,防止过大granule带来的性能消耗) | alter system set sga_max_size=待定 scope=spfile sid='*'; |
| shared_pool_size | 0 | max(1g,sga_target*15%)为最小值
按需设置 |
SQL缓冲池,应用程序决定,建议手动设置shared_pool,如果在10g生产值基础上按照以下算法设置11g值:11g size = 10g size + max( 10g size * 0.3, 1g) ;如果在11g生产值基础上按照以下算法设置12c值:12c size = 11g size + max( 11g size * 0.2, 1g);如果是新安装初始值,建议设置max(1g,sga_target*15%)最小值 | alter system set shared_pool_size=待定 scope=spfile sid='*'; |
| standby_file_management |
|
AUTO |
|
alter system set standby_file_management=AUTO scope=spfile sid='*'; |
| streams_pool_size |
|
128M最小值
OGG按需设置 |
流池,应用程序决定,推荐值为128M,如果需要使用OGG IE模式需要增加 | alter system set streams_pool_size=1024M scope=spfile sid='*'; |
| temp_undo_enabled | FALSE | FALSE | 保持默认值,TEMP_UNDO_ENABLED is a new feature in 12c. it helps in reducing the amount of redo caused by DML
# on global temporary tables |
alter system set temp_undo_enabled=FALSE scope=spfile sid='*'; |
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