RE: Add column(s) to an existing table

Um...deleting rows? Or are you talking about dropping a column? Yes, deleting rows would need to visit all the affected blocks.  

If you're talking about dropping a column, you can mark it as unused and then do the actual deletion/cleanup later....  

-Mark  

-- 
Mark J. Bobak 
Senior Oracle Architect 
ProQuest Information & Learning 

Ours is the age that is proud of machines that can think and suspicious
of men who try to.  --H. Mumford Jones, 1892-1980

 



________________________________


From: Roger Xu [mailto:Roger.Xu_at_dp7upbg.com] 
Sent: Tuesday, August 01, 2006 5:57 PM
To: Bobak, Mark; Oracle-L_at_Freelists. Org (E-mail)
Subject: RE: Add column(s) to an existing table


Deleting has to visit every row immediately, right? Thanks, Roger

	-----Original Message-----
	From: Bobak, Mark [mailto:Mark.Bobak_at_il.proquest.com]
	Sent: Tuesday, August 01, 2006 4:55 PM
	To: Roger Xu; Oracle-L_at_Freelists. Org (E-mail)
	Subject: RE: Add column(s) to an existing table
	
	
	Adding columns to a table of any arbitrary size is simply a DDL
(data dictionary) operation.  The only reason you'd need to visit every
row is if the column you were adding was specifying a non-null default
value.
	 
	-Mark
	 

	-- 
	Mark J. Bobak 
	Senior Oracle Architect 
	ProQuest Information & Learning 

	Ours is the age that is proud of machines that can think and
suspicious of men who try to.  --H. Mumford Jones, 1892-1980

	 



________________________________


	From: oracle-l-bounce_at_freelists.org
[mailto:oracle-l-bounce_at_freelists.org] On Behalf Of Roger Xu
	Sent: Tuesday, August 01, 2006 5:50 PM
	To: Oracle-L_at_Freelists. Org (E-mail)
	Subject: Add column(s) to an existing table
	
	
	Hi List, 
	

		

			Does the following SQL touch every single row
immediately?

			ALTER TABLE supplier
			ADD (supplier_tax_id varchar2(10),
			            supplier_timezone varchar2(5) ); 

			What is the best way to add column(s) to an
existing table with millions of rows?

			Thanks,

			Roger


	This e-mail is intended solely for the person or entity to which
it is addressed and may contain confidential and/or privileged
information. Any review, dissemination, copying, printing or other use o
	


____________________________________________________________________

	This email has been scanned for all viruses by the MessageLabs
Email Security System.
	


This e-mail is intended solely for the person or entity to which it is
addressed and may contain confidential and/or privileged information.
Any review, dissemination, copying, printing or other use o


____________________________________________________________________

This email has been scanned for all viruses by the MessageLabs Email
Security System.


--
http://www.freelists.org/webpage/oracle-l