Oracle442 Application Instances ---------- initialize parameter files and oracle initialize parameter files

Oracle442 Application Instances ---------- initialize parameter files and oracle initialize parameter files

---------------- Initialize the parameter file --------------------
Before 9i, the initialization parameter file used by oracle is pfile. 9i started to reference SPFILE but kept pfile.

Parameter file initialization plays a key role in the entire ORACLE System. During the startup process, oracle assigns SGA Based on the initialization parameter settings to start the background process. After the database is opened, you can set the initialization parameters to run the database.

For oracle Versions later than 9I, the initialization parameter files include spfileSID. ORA, spfile. ORA, and init. ORA. oracle searches for the initialization parameter files in sequence during startup. If not, the database fails to be started and Alert_sid.log reports an error.

For Versions later than 9i, spfile is enabled by default. Of course, you can also specify the pfile parameter file to start ORACLE. The format of the spfile parameter file is spfileSID. ORA. The format of the pfile parameter file is initSID. ORA:

Startup pfile = '/oradata/oracle/admin/TEST/pfile/init. ora .*****

In addition, pfile and spfile can be created for each other. The default directory is $ ORACLE_HOME/dbs /.

Create spfile from pfile;

Create pfile from spfile;

The format of the initialization parameter created through spfile is: initSID. ORA

You can modify the initialization parameters in either of the following ways:

1. Modify the initialization parameters under commond:
Modify pfile parameters: Edit init. ora.
Modify spfile parameters: the parameter file cannot be edited. You can only use commands or EM to dynamically modify initialization parameters.
Command: Alter system set AAA = N scope = MEMORY | SPFILE | BOTH;
The SCOPE parameter has three options:
MEMORY: the modification is only valid for running instances.
SPFILE: Modify the SPFILE settings.
BOTH: The SPFILE and the instance are modified at the same time.
Note: You must specify the SPFILE parameter when modifying static parameters. Otherwise, an error is reported. That is, when modifying static parameters, the SCOPE parameter cannot be BOTH.

2. Modify the initialization parameter settings in EM:
1. log on to EM as a sys user.
2. Select the manage tag button on the main interface;
3. On the Management page, select "all initialization parameters" under "Database Configuration". Go to the initialization parameter settings page:
4. The default setting is SCOPE = MEMORY. When "the application and SPFile will be changed in the currently running instance mode ." When the check box is selected, it is equivalent to SCOPE = BOTH settings. Enter a new value in the value text box, and click the Apply button in the upper-right corner. The modification takes effect.
5. modify attributes to SCOPE = SPFILE. The modification procedure is the same as modifying attributes to SCOPE = MEMORY.

Bytes ------------------------------------------------------------------------------------

Application Scenario 32: Initialize parameter management
Create an initialization parameter file
Create a pfile
You can directly copy a pfile file and start the database using syartup pfile =, or log on to SQL * plus as sysdba and run the following command:
SQL> create pfile = '... init. ora'
From spfile = '..:... spfile. ora'
Or run the command without parameters:
SQL> create pfile from spfile
This name will create a pfile under oracle_homedatabase. The default name is init <SID>. ora.
Create a spfile File
Since spfile is a binary file, it cannot be copied or pasted directly. You can use this command to create a new spfile through pfile.
SQL> create spfile = '...: spfile. ora'
From pfile = '... init. ora'

Configure the initialization parameter file
Run the following command:
SQL> alter system set parameter name = parameter value spoce = spfile | memory | both

Application Scenario 33: Use the show parameters statement to display initialization PARAMETERS

Show parameters [<start string>];

Eg: show parameters db

Application Scenario 34: Use the V $ PARAMETER view to view initialization PARAMETER information

Log On As the SYS administrator and view the initialization parameters starting with db:
Select name, VALUE, DISPLAY_VALUE from v $ parameter where name like '% db % ';
Run the following command to set the width of each column:
Col name format A20
Col value format A20
COL DISPLAY_VALUE FORMAT A20

Application Scenario 35: Use the alter system statement to set initialization parameters

Alter system <parameter name >=< parameter value>
<SCOPE clause>
The SCOPE clause specifies the applicability of parameter changes. The following values can be used:
1. SPFILE. The change is only valid for SPFILE files.
2. MEMORY. The value changed by the application in the memory.
3. BOTH. Changes are applied to both SPFILE files and memory.
Eg: alter system set SGA_MAX_SIZE = 1g scope = SPFILE;