Re: Newbie: Creating new database files

"joel garry" <joel-garry_at_home.com> wrote in message news:1162938955.965716.154040_at_f16g2000cwb.googlegroups.com...
>
> Ade wrote:
>> "Brian Peasland" <dba_at_nospam.peasland.net> wrote in message
>> news:J831tt.GL5_at_igsrsparc2.er.usgs.gov...
>> > Geoff Muldoon wrote:
>> >> jim_at_ponder-stibbons.com says...
>> >>
>> >>> Muldoon <geoff.muldoon_at_trap.gmail.com> writes
>> >>>> But *why* you'd bother
>> >>>> to set up separate tablespaces for each schema/user (read that as
>> >>>> each
>> >>>> "database" in Access terms) just to simulate what you used to do in
>> >>>> Access
>> >>>> is the real question. I can't think of a decent reason why you
>> >>>> would.
>> >>>>
>> >>> Separating applications by tablespace is a very common practice.
>> >>
>> >> Commonly done doesn't necessarily mean sensibly done. I've seen
>> >> similar
>> >> debates here about the supposed benefits of separating tables and
>> >> indexes
>> >> into separate tablespaces. Advantages of separate tablespaces per app?
>> >>
>> >> Geoff M
>> >
>> > Another reason to keep your app's segments in separate tablespaces is
>> > to
>> > help you keep one app's activity from affecting another as much as
>> > possible. If AppA and AppB are in the same tablespace and AppA has some
>> > rogue process extending a table by a large amount, AppB might run out
>> > of
>> > free space that it needs. In addition, I can put AppA's segments on a
>> > set
>> > of disk volumes and keep AppB's segments on another set of disk
>> > volumes,
>> > ensuring the I/O from the two apps are seperate. You cannot do this if
>> > they are in the same tablespace. Also, Tablespace Point In Time
>> > Restores
>> > will affect more than one app if you put all of the segements in the
>> > same
>> > tablespace.
>> >
>> > I always make it part of my "best practices" to never mix application's
>> > segments in the same tablespace. This is not from any performance
>> > standpoint, but for reasons of manageability. And I consider all of the
>> > above...plus what Joel added...as being very sensible.
>> >
>> >
>> > HTH,
>> > Brian
>> >
>> >
>> > --
>> > ===================================================================
>> >
>> > Brian Peasland
>> > dba_at_nospam.peasland.net
>> > http://www.peasland.net
>> >
>> > Remove the "nospam." from the email address to email me.
>> >
>> >
>> > "I can give it to you cheap, quick, and good.
>> > Now pick two out of the three" - Unknown
>>
>>
>> Brian,
>>
>> This sounds exactly like what I would like to achieve. Although I'm a
>> newbie
>> to Oracle, I have spent many years using OpenVMS on Vaxes and Alphas,
>> specifically utilising the proprietary RMS record management system using
>> several legacy programming languages. I very much appreciate the need to
>
> Whoa, that takes me back! Which languages?
>
>> keep potentially conflicting applications apart for disk I/O and security
>> reasons. but my question still remains; how do I achieve this under
>> Oracle
>> 10g Express Edition? (hey - it was free, OK?? :-) )
>
> Be careful, there are myths floating about regarding disk I/O. Do you
> actually have three or more disk devices?

>
> jg
> --
> @home.com is bogus.
> "Eighties - I'm living in the Eighties - I push
> Eighties - I saw the worlds begin to march
> Eighties - I'm living in the Eighties - I struggle
> Eighties - I saw the worlds begin to march " - Killing Joke
>

Hi, to answer your question, COBOL, C, Basic, Fortran, Macro Assembler and Powerhouse

No I don't have separate disks on my home PC. The main reason here is to keep the database files for each application away from other apps.

I have learnt quite a bit about tablespaces over the last week or so, especially the fact that Oracle 10g Express won't, in itself, let you create any within the GUI. However, using the SQLPLUS that comes along with it is a different matter. In that you can manipulate the entities (for want of a better word) a whole lot better.

I still can't find the command to extend a file once created though. I initially entered the following;

SQL> create tablespace datafile 'c:\trash\my_tablespace.dbf' size 200000;

I then had a look in the directory and saw the 200,000 byte file (I was kind of expecting it in 512 byte blocks - oh well that's VMS for ya!) so I decided to try to extend it but couldn't find the command.

Looking on the web, I have found that you should initialize to what you think should last for a while and include the extend clause in the create statement. Still wouldn't mind a single command to extend it though.

Thanks to all,

Ade Received on Wed Nov 08 2006 - 05:36:15 CST