Oracle 参数 PRE_PAGE_SGA 官方解释，作用，如何配置最优化建议
本站中文解释
PRE_PAGE_SGA：表示进程在登陆实例时是否进行SGA预分配，即把SGA中需要分配的内存预分配给进程，避免过程发生频繁的内存申请操作影响性能。
正确设置：
1.使用SQLPlus登录数据库，使用sysdba账号操作；
2.设置PRE_PAGE_SGA参数，使用以下语句：
alter system set PRE_PAGE_SGA=True scope=spfile;
3.重启Oracle数据库实例，使用以下语句：
shutdown immediate;
startup;
官方英文解释
PRE_PAGE_SGA determines whether Oracle accesses the entire SGA at instance startup.
Operating system page table entries are then prebuilt for each page of the SGA.
| Property | Description |
|---|---|
|
Parameter type |
Boolean |
|
Default value |
|
|
Modifiable |
No |
|
Modifiable in a PDB |
No |
|
Range of values |
|
|
Basic |
No |
When this parameter is set to true, the database server touches the entire SGA after the instance startup. These accesses are done by a background process and are initiated after the instance startup. The accesses cause the OS to allocate memory to the SGA and populate the page tables, making the SGA memory resident and increasing database performance.
Note:
This setting does not prevent your operating system from paging or swapping the SGA after it is initially read into memory.
