Call now: 252-767-6166  
Oracle Training Oracle Support Development Oracle Apps

 
 Home
 E-mail Us
 Oracle Articles
New Oracle Articles


 Oracle Training
 Oracle Tips

 Oracle Forum
 Class Catalog


 Remote DBA
 Oracle Tuning
 Emergency 911
 RAC Support
 Apps Support
 Analysis
 Design
 Implementation
 Oracle Support


 SQL Tuning
 Security

 Oracle UNIX
 Oracle Linux
 Monitoring
 Remote s
upport
 Remote plans
 Remote
services
 Application Server

 Applications
 Oracle Forms
 Oracle Portal
 App Upgrades
 SQL Server
 Oracle Concepts
 Software Support

 Remote S
upport  
 Development  

 Implementation


 Consulting Staff
 Consulting Prices
 Help Wanted!

 


 Oracle Posters
 Oracle Books

 Oracle Scripts
 Ion
 Excel-DB  

Don Burleson Blog 


 

 

 


 

 

 
 

 

ASM Template Tips

Oracle Database Tips by Donald BurlesonJanuary 29, 2013

Question:  Can you explain how the Oracle ASM diskgroup templates work?  I understand that a template can be attached to a disk group by I do not understand when you use the "alter diskgroup xxx add template" command, when the template is used.

Answer:  In plain English, an ASM template is a collection of attributes that can be created and deployed to multiple diskgroups.  The attributes within the definition in an ASM diskgroup are applied when you create data files within the diskgroup, and the attributes apply to the data files.

Collections of attributes used by ASM during file creation are known as templates. Templates are used to simplify ASM file creation by mapping complex file attribute specifications into a single named object (template). Each Oracle file type has its own default template. Each disk group contains its own set of definition templates. Template names only have to be unique within a single ASM disk group, a template of the same name can exist in different disk groups with each separate template having their own unique properties.

Prior to Oracle 10g you were forced to use the "add template" syntax to add attributes to an ASM diskgroup, whereas in 11g and beyond the "template" command is superseded by the "add attribute" command.

Here is a list of the "default" (built-in) templates and their attributes:

Template name Striping Mirroring when using a normal redundancy disk group Mirroring when using a high redundancy disk group Mirroring when using an external redundancy disk group
Controlfile Fine 3-Way Mirroring 3-Way Mirroring No Mirroring
Datafile Coarse 2-Way Mirroring 3-Way Mirroring No Mirroring
Onlinelog Fine 2-Way Mirroring 3-Way Mirroring No Mirroring
Archivelog Coarse 2-Way Mirroring 3-Way Mirroring No Mirroring
Tempfile Coarse 2-Way Mirroring 3-Way Mirroring No Mirroring
Backupset Coarse 2-Way Mirroring 3-Way Mirroring No Mirroring
Parameterfile Coarse 2-Way Mirroring 3-Way Mirroring No Mirroring
Dataguardconfig Coarse 2-Way Mirroring 3-Way Mirroring No Mirroring
Flashback Fine 2-Way Mirroring 3-Way Mirroring No Mirroring
Changetracking Coarse 2-Way Mirroring 3-Way Mirroring No Mirroring
Dumpset Coarse 2-Way Mirroring 3-Way Mirroring No Mirroring
Xtransport Coarse 2-Way Mirroring 3-Way Mirroring No Mirroring
Autobackup Coarse 2-Way Mirroring 3-Way Mirroring No Mirroring

In addition to these "named" templates you can also create user-defined templates.  These user-defined templates appear in the "name" column of the v$asm_template view.

When you first create a diskgroup, Oracle creates a "default" template.  This default template includes attributes such as the type of mirroring (2-way or 3-way) and whether the data files are to be coarse or fine striped:

alter diskgroup
   mygroup1
add template
   mytemplate1
attributes
   (mirror, fine);

Administrators can change the attributes of the default templates or add their own templates. This lets an administrator specify the appropriate file creation attributes as a template. However, if a DBA needs to change an ASM file attribute after a file has been created, then the file must be copied using RMAN into a new file created with a different template that contains the new attributes.

When you create a disk group, Oracle creates system default template for the disk group. It includes default attributes for various file types like control files or data files. The DBA can mention whether the files created via the template should be 2-way or 3-way mirrored and Coarse or fine striped.

The "add template" syntax is optional and if you do not assign a template to a diskgroup, Oracle will apply a default template for you.

There is a v$asm_attribute view to support ASM template attributes:

select
   group_number,
   name,
   value

from
   v$asm_attribute

order by
   group_number,
   name;

The v$asm_template has group_number and v$asm_attribute has group_number, and this supports that each template group may have many attributes.

 

 
Get the Complete
Oracle SQL Tuning Information 

The landmark book "Advanced Oracle SQL Tuning  The Definitive Reference"  is filled with valuable information on Oracle SQL Tuning. This book includes scripts and tools to hypercharge Oracle 11g performance and you can buy it for 30% off directly from the publisher.

 

 

Burleson is the American Team

Note: This Oracle documentation was created as a support and Oracle training reference for use by our DBA performance tuning consulting professionals.  Feel free to ask questions on our Oracle forum.

Verify experience! Anyone considering using the services of an Oracle support expert should independently investigate their credentials and experience, and not rely on advertisements and self-proclaimed expertise. All legitimate Oracle experts publish their Oracle qualifications.

Errata?  Oracle technology is changing and we strive to update our BC Oracle support information.  If you find an error or have a suggestion for improving our content, we would appreciate your feedback.  Just  e-mail:  

and include the URL for the page.


                    









Burleson Consulting

The Oracle of Database Support

Oracle Performance Tuning

Remote DBA Services


 

Copyright © 1996 -  2017

All rights reserved by Burleson

Oracle ® is the registered trademark of Oracle Corporation.

Remote Emergency Support provided by Conversational

 

 

��  
 
 
Oracle Training at Sea
 
 
 
 
oracle dba poster
 

 
Follow us on Twitter 
 
Oracle performance tuning software 
 
Oracle Linux poster