Oracle modification parameters
Oracle database is one of the most popular databases in the world. In order to ensure its efficient and stable operation, administrators often need to adjust some key parameters. This article will introduce how to modify parameters in the Oracle database to improve the performance and reliability of the database.
1. Check the database parameters
Before modifying the database parameters, we need to check the current database parameters and understand their meaning and configuration. You can run the following command to view:
SELECT name, value, isdefault, description FROM v$parameter ORDER BY name;
This command will display the current parameter settings, default values, description information and whether it is the default value of the database. Among them, name is the parameter name, value is the value of the current parameter setting, isdefault indicates whether it is the default value, and description is the description information of the parameter.
2. Modify database parameters
To modify parameters manually, you can use the ALTER SYSTEM command. The syntax of this command is as follows:
ALTER SYSTEM SET 参数名称=新值 [SCOPE=内部修饰符];
The parameter name indicates the parameter name to be modified, and the new value indicates the modified parameter value. SCOPE is an optional SESSION, SID, or BOTH that specifies which dimension the modification will affect.
For example, the following command will modify the database sga_max_size parameter to 8192MB:
ALTER SYSTEM SET sga_max_size=8192M SCOPE=SPFILE;
The same is true for modifying the parameters in the PFILE file Common methods. Oracle database will configure the database according to the parameters in the PFILE or SPFILE file when it is started. Modifying the PFILE file requires manually restarting the database after modification, while modifying the SPFILE file requires using the following command:
CREATE PFILE='<pfile路径>' FROM SPFILE;
Once the SPFILE file is modified, the database must be restarted for the parameters to take effect. You can use the following command to modify parameters in SPFILE:
ALTER SYSTEM SET 参数名称=新值;
For example, the following command will modify the database sga_max_size parameter to 8192MB:
ALTER SYSTEM SET sga_max_size=8192M;
3. Settings of common parameters
Understand common parameters Parameter setting is very important for database administrators. The following are some common Oracle parameters and their meanings:
4. Notes
You need to pay attention to the following when modifying Oracle database parameters:
In short, modifications to Oracle database parameters need to be carried out according to specific circumstances and require profound database technology and experience. This article describes how to modify parameters in Oracle Database to improve database performance and reliability. You need to pay attention to various precautions when modifying parameters to effectively optimize the performance and stability of the database.
The above is the detailed content of oracle modify parameters. For more information, please follow other related articles on the PHP Chinese website!