oracle modification instance

Oracle is a very popular relational database management system. When using an Oracle database, sometimes the database instance needs to be modified to meet specific needs. This article will introduce how to modify an Oracle instance.

First, we need to understand the concept of Oracle instances. An Oracle instance refers to a collection of processes started from the computer running the Oracle database software when the database is managed. It is a running environment of the database, including the Oracle Server process and other accompanying programs, such as program buffer managers and background processes. Oracle instances include database instances, control files, log files, data files, etc.

Before modifying the Oracle instance, we need to understand the basic structure of the Oracle instance. An Oracle instance consists of the following components:

1. SGA (shared memory area): includes the buffer area, shared pool and large SGA components.
2. Process: Oracle instance includes multiple processes, including SGA port process, background process and foreground process.
3. Database instance: Oracle instance includes multiple database instances, including control files, log files and data files.

Now, let’s introduce how to modify the Oracle instance.

1. Stop the Oracle instance

Before modifying the Oracle instance, we need to stop it first. Use the following command to stop the Oracle instance:

$ sqlplus /nolog
SQL> connect / as sysdba
SQL> shutdown immediate;

This command will shut down the instance immediately. When you want to modify the parameters of an Oracle database instance, you must modify the parameters after closing the instance.

2. Modify Oracle instance parameters

You can use SQL*Plus tools to modify Oracle instance parameters, as shown below:

$ sqlplus sys/oracle as sysdba
SQL> alter system set parameter_name=new_value;

Here, parameter_name is the parameter name to be modified, new_value is the new value of the parameter.

3. Start the Oracle instance

After modifying the Oracle instance parameters, you need to start the instance. You can use the following command to start:

$ sqlplus /nolog
SQL> connect / as sysdba
SQL> startup;

This command will start a new Oracle instance and load new parameter values. If there is a problem with the modified parameters, you can use the above command to start the old instance.

Summary:

This article describes how to modify an Oracle instance to meet specific needs. Before modifying the Oracle instance, you need to stop the instance, modify the parameters, and then restart the instance. How you modify instance parameters depends on the specific needs of each instance. Therefore, before modifying the instance, you should ensure that you understand the components and structure of the Oracle instance in order to perform the modification operation effectively.

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