Re: Altering a column type - Most efficient way

On Thu, 2008-07-10 at 09:57 -0400, Alvaro Herrera wrote:
> Ow Mun Heng wrote:
> 
> > This is what I see on the table
> > 
> > NEW attypmod = -1
> > OLD attypmod =  8
> 
> 8 means varchar(4) which is what you said you had (4+4)
> -1 means unlimited size.
> 

This is cool. 

If it were this simple a change, I'm not certain why (I believe) PG is
checking each and every row to see if it will fit into the new column
definition/type. 

Thus, I'm still a bit hesitant to do the change, although it is
definitely a very enticing thing to do. ( I presume also that this
change will be instantaneous and does not need to check on each and
every row of the table?)

Thanks./