Re: changing columns to not null one or many at a time

Greg Caulton <gcaulton_at_sympatico.ca> wrote in message news:<3C1E39F9.1080907_at_sympatico.ca>...
> Oracle v7.3.2.1
> I tested with a large table on AIX with no user access and it appears that
>
> alter table LARGE_TABLE modify
> (COLUMN1 not null,COLUMN2 not null,COLUMN3 not null, COLUMN4 not null)
> /
>
> completes at the SAME speed as:
>
> alter table LARGE_TABLE modify (COLUMN1 not null)
> /
> alter table LARGE_TABLE modify (COLUMN2 not null)
> /
> alter table LARGE_TABLE modify (COLUMN3 not null)
> /
> alter table LARGE_TABLE modify (COLUMN4 not null)
> /
>
> Is this due to the former statement actually fixing one column at a time
> OR that the tables blocks are in memory for consequent alters on the
> same table.
>
> thanks
>
> Greg

yes you have got it right
the second method is faster because of the fact that the tables blocks are in memory for subsequent alters on the same table Received on Tue Dec 18 2001 - 05:20:51 CET