====== Oracle: SPFile and PFiles ======

Oracle reads its parameters from a file called "SPFile".
You can't change it directly as it's a binary file.
Additionally, Oracle can read the parameters from "PFiles", which are regular text files.

===== Create PFile =====

To export the SPFiles to a PFile, just enter the following in SQLplus:

<code sql>
CREATE PFILE FROM SPFILE;
</code>

It will create a PFile ''${ORACLE_HOME}/dbs/init${ORACLE_SID}.ora''.

===== Import PFile =====

To import the parameters from the PFile to the SPFile, you have to boot the instance from the PFile and the write the SPFile. You have to enter the path to the PFile instead of ${PATH_TO_PFILE}.

<code sql>
SHUTDOWN IMMEDIATE;
STARTUP NOMOUNT PFILE='${PATH_TO_PFILE}'
CREATE SPFILE FROM PFILE;
SHUTDOWN IMMEDIATE;
</code>

If your PFile is located at ''/db/oracle/config/pfiles/initweb.ora'', the the second line would be:

<code sql>
STARTUP NOMOUNT PFILE='/db/oracle/config/pfiles/initweb.ora'
</code>

===== Initialization Parameters =====

==== Flash Recovery Area ====

=== DB_RECOVERY_FILE_DEST_SIZE ===

The parameter ''DB_RECOVERY_FILE_DEST_SIZE'' specifies the size of the flash recovery area.

  * For more inforamtion, see the documentation: [[http://download.oracle.com/docs/cd/B19306_01/server.102/b14237/initparams054.htm#REFRN10235|10.2]] [[http://download.oracle.com/docs/cd/E11882_01/server.112/e10820/initparams063.htm#REFRN10235|11.2]]

Example: Set flash recovery area to 8GB. The usage of ''SCOPE=BOTH'' changes the init param in memory and in the SPFile.

<code sql>
ALTER SYSTEM SET DB_RECOVERY_FILE_DEST_SIZE=8G SCOPE=BOTH SID='*';
</code>

{{tag>admin oracle}}