Re: Autoextend

Jason

It is in Oracle8. The view DBA_DATA_FILES has column AUTOEXTENSIBLE, MAXBYTES, MAXBLOCKS, and INCREMENT_BY.

In 7.3, look at FILEXT$ (I can never remember if that has two E's or not). Rows are put into this table only where files have extended, not before.

Going back to the discussion of when it's relevant or not to autoextend, what it really boils down to is a discussion that Tom Kyte and I had on this same topic some time ago. I prefer not to use AUTOEXTEND, because I like to minimize the damage of rogue processes. Tom's view is that he likes to use it because he can't be a full-time DBA on his database due to other commitments, so it's easier to have the files grow rather than have users hit errors. Both viewpoints are equally valid to my way of thinking.

HTH. Pete

Jason Salter wrote:

> On Fri, 01 Oct 1999 10:03:36 -0400, Kenneth C Stahl
> <BlueSax_at_Unforgettable.com> wrote:
>
> >This is one of those oracle questions that can best be answered by "it
> >depends". For some tablesspaces it can be a good idea but for others it
> >might be a poor choice. It also depends on space availability on the disk.
> >On a UNIX system with large availablity in the slice where the datafile
> >exists then autoextend might work out, but if there is only limited space
> >you might want to add another datafile on a different slice.
> >
> >My general experience has been that once I turn autoextend on I have to pay
> >attention to what happens with the datafiles. If I allow autoextend on the
> >tablespace where my rollback segments reside I usually will shrink the
> >datafiles back to a more reasonable size if they have been autoextended due
> >to some large transaction.
> >
> >My suggestion is that you give some thoughts to your goals, the system
> >capacity, the usage of the tablespaces and then make a decision for each
> >tablespace of how you want to treat handle it.
> >
> >Frank Calfo wrote:
> >>
> >> Is autoextend a good feature to turn on or is it better to leave it off and
> >> add datafiles manually as needed?
> >>
> >> Is there any performance advantage in using or not using autoextend?
>
> Another thing, where can you look to find out if autoextend has been
> turned on or not?
>
> I've looked in dba_data_files and v$datafile's but it's not either of
> those.
>
> Jason.

Received on Fri Oct 01 1999 - 11:02:28 CDT