Tag Archives: alter system

11g, Oracle, Oracle 10g, oracle 9i

Changing init parameters with an SPFILE:

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Since Oracle 9i, Oracle has introduced the use of SPFILE over INIT files for control of the RDBMS initialization parameters. The introduction of SPFILE was to allow for the dynamic changing of initialization parameters setting while the database is up and eliminating the need to open an OS layer file to make changes to the ORACLE initialization parameters. This article will cover: how to change initialization parameter from within an Oracle database. This procedure is the same on any OS.

1. Logon to your Oracle database server as the Oracle software owner.

2. Connect to SQLPLUS with SYSDBA privileges.

mylinux :> sqlplus ‘/ as SYSDBA’

SQL*Plus: Release 10.2.0.4.0 – Production on Sun Sep 27 09:49:04 2009

Copyright (c) 1982, 2007, Oracle. All Rights Reserved.

Connected to:
Oracle Database 10g Enterprise Edition Release 10.2.0.4.0 – 64bit Production
With the Partitioning, OLAP, Data Mining and Real Application Testing options

SQL>

3. We use the alter system command to change initialization parameters from within the Oracle database while an SPFILE is in use. The following is an example of the alter system command.

alter system set {initialization_parameter} = {new_value} scope = {scope}

4. The key here is the scope clause which can have three possible values:

MEMORY – No changes are made to the SPFILE at all and the change is only mode in the current instance. To use this option, the initialization parameter must be dynamic and modifiable.

BOTH – Changes are made both in the current instance and in the SPFILE for future restart of the database. To use this option, the initialization parameter must be dynamic and modifiable.

SPFILE – Changes are not made in the current instance and the SPFILE is updated with new initialization parameter setting; however it will only take affect on restart of the database.

5. Examples of changing initialization parameter with alter system command:

SQL> alter system set user_dump_dest = ‘/opt/oracle/udump’ scope=both;

System altered.

SQL> alter system set user_dump_dest = ‘/opt/oracle/udump ‘ scope=memory;

System altered.

SQL> alter system set audit_file_dest=’/opt/oracle/udump ‘ scope=spfile;

System altered.

This completes adjusting initialization parameters in an SPFILE.

Larry J. Catt, OCP 9i, 10g
oracle@allcompute.com
www.allcompute.com

Oracle, Oracle 10g

Oracle Temporary Tablespace Movement

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Temporary tablespace’s in the Oracle environment are used for sorting and other non-permanent data operations. Although the space in a temporary tablespace is not permanent, a database of any size cannot properly function without the use of very large amounts of temporary tablespace. This procedure covers the movement of a temporary tablespace after space on the original storage device becomes insufficient. We will cover the movement of the TEMPORARY tablespace from the mount point data1 to mount point data3.

1. Find all tablespaces defined as TEMPORARY

SQL> select tablespace_name from dba_tablespaces where contents=’TEMPORARY’;

TABLESPACE_NAME
——————————
TEMP
TEMPORARY

SQL>

2. Locate the temp_files in the temporary tablespace.

SQL> select file_name from dba_temp_files where tablespace_name = ‘TEMPORARY’;

FILE_NAME
/data1/temporary01.dbf
/data1/temporary02.dbf
/data1/temporary03.dbf

SQL>

3. Find size of current files

SQL> select file_name, bytes/1024/1024 from dba_temp_files where tablespace_name = ‘TEMPORARY’;
FILE_NAME BYTES/1024/1024
—————— —————
/data1/temporary01.dbf 4096
/data1/temporary02.dbf 2048
/data1/temporary03.dbf 2048

SQL>

4. Add new temp files on your new mount point to the tablespace temporary with the command ‘alter tablespace’.

SQL> alter tablespace temporary add tempfile ‘/data3/temporary01.dbf’
size 4096m;
Tablespace altered.

SQL> alter tablespace temp add tempfile ‘/data3/temprary02.dbf’
size 2048m;
Tablespace altered.

SQL> alter tablespace temp add tempfile ‘/data3/temprary03.dbf’
size 2048m;
Tablespace altered.

5. Shutdown database to free all in-use segments of the temporary tablespace TEMPORARY with the command ‘shutdown immediate’.

SQL> shutdown immediate
Database closed.
Database dismounted.
ORACLE instance shut down.
SQL>

6. Startup the database in restricted mode using the command ‘startup restict’ so no user activity can pickup segments from the tablespace TEMPORARY.

SQL> startup restrict
ORACLE instance started.

Total System Global Area 612368384 bytes
Fixed Size 1250428 bytes
Variable Size 159386500 bytes
Database Buffers 444596224 bytes
Redo Buffers 7135232 bytes
Database mounted.
Database opened.
SQL>

7. Drop the old datafiles using the command ‘alter database’

SQL> alter database tempfile ‘/data1/temprary01.dbf’
drop including datafiles;
Database altered.

SQL> alter database tempfile ‘/data1/temprary02.dbf’
drop including datafiles;
Database altered.

SQL> alter database tempfile ‘/data1/temprary03.dbf’
drop including datafiles;
Database altered.

8. View the new temp files with the following command.

SQL> select file_name from dba_temp_files where tablespace_name=’TEMPORARY’;
FILE_NAME
———————–
/data3/temprary01.dbf
/data3/temprary02.dbf
/data3/temprary03.dbf

SQL>

9. Open the database for normal use with ‘alter system’ command.

SQL> alter system disable restricted session;

System altered.

SQL>

This completes the movement of temporary tablespaces tempfiles.

Larry J Catt, OCP 9i, 10g
oracle@allcompute.com
www.allcompute.com