Oracle FAQ | Your Portal to the Oracle Knowledge Grid |
Home -> Community -> Usenet -> c.d.o.server -> Re: OFA and file extension naming conventions
"Snid" <snid_at_snider.sno> wrote in message
news:c3vqre$a1d$1_at_bunyip.cc.uq.edu.au...
> So do you believe that oracle should keep calling tempfiles datafiles and
> that it is a good naming convention even though they can't be hot backed
up
> and that oracle treats them differently to dba_data_files?
Yes, because they *are* data files.
Do you want to stick a different extension on system01.dbf because you can't take it offline?
> One can no longer say that you only need to backup datafiles.
One never did say that one only needs to backup datafiles. There are control files and archive logs as well to think about. ;-)
Otherwise, I don't see your argument... you can't backup tempfiles, not with 'alter tablespace' commands anyway; and you shouldn't bother doing so whatever method you choose, since recovery of TEMP is simply to drop it and re-create it. So given that, and ignoring the archives and control files for the moment, it remains the case as it always has that you do indeed only need to worry about backing up those things which are listed in v$datafile or dba_data_files.
But who cares anyway? It's just a name. You can call 'em what you like, and it makes no difference.
Regards
HJR
> "Howard J. Rogers" <hjr_at_dizwell.com> wrote in message
> news:40627e93$0$31904$afc38c87_at_news.optusnet.com.au...
> |
> | "Snid" <snid_at_snider.sno> wrote in message
> | news:c3tla8$tum$1_at_bunyip.cc.uq.edu.au...
> | > Hmmn, Ok.
> | >
> | > I guess I just look at tempfiles (files that exist in dba_temp_files)
> | > differently to datafiles (files that exist in dba_data_files) as you
> don't
> | > really need to back them up.
> |
> |
> | Not only do you not "need" to back them up, you can't back them up. You
> | cannot issue 'alter tablespace X begin backup' commands, when the data
> files
> | associated with that tablespace are known to be tempfiles.
> |
> | So what, however? You can't take a datafile called system01.dbf offline
or
> | make system01.dbf read-only either.
> |
> | Functionality is one thing, and the physics are something else.
> Physically,
> | they're data files.
> |
> | > Also, the fact that oracle segregates tempfiles from datafiles by
using
> | the
> | > two tables from above makes me think of them as different so I thought
> | that
> | > maybe a different extension might be applicable.
> |
> | The reason it did that, fundamentally, goes back to the inability to put
a
> | temp file into hot backup mode. A lot of people perform user-managed
> backups
> | via scripts, and those scripts dynamically work out what to backup by
> | looking at (for example) v$datafile. It obviously wouldn't do to have
> | entries appearing in that view (and hence in the dynamically-created
> backup
> | scripts) which will produce errors when 'begin backup' commands are
> | attempted against them. Hence the need to separate them out from each
> other.
> |
> | But again, just because I see table A, B, C and D when I query
ALL_TABLES
> | and only tables A & C when I query USER_TABLES doesn't mean that B and D
> | aren't really tables.
> |
> | Regards
> | HJR
> |
> |
> |
> | >
> | > But yes, oracle does call tempfiles temporary datafiles or vice versa.
> | >
> | >
> | >
> | >
> | >
> | > "Howard J. Rogers" <hjr_at_dizwell.com> wrote in message
> | > news:40624469$0$31901$afc38c87_at_news.optusnet.com.au...
> | > |
> | > | "Snid" <snid_at_snider.sno> wrote in message
> | > | news:c3tg0n$354$1_at_bunyip.cc.uq.edu.au...
> | > | > Under OFA it says that data files (datafiles) should end with a
.dbf
> | > | > extension; however, it doesn't mention what temporary files
> | (tempfiles,
> | > | temp
> | > | > files) should end in.
> | > | >
> | > | > I don't think that tempfiles should end with a .dbf extension as
> they
> | > | aren't
> | > | > datafiles.
> | > |
> | > | Yes they are. What makes you think they're not? The contents of the
> | files
> | > | are different, for sure, in the sense that you don't care about it
on
> a
> | > | long-term basis. But even then, they've got Oracle blocks inside
them
> | with
> | > | headers and so on.
> | > |
> | > | The only difference between a "normal" data file and a temp file is
> that
> | > the
> | > | latter are created initially sparse (like when you touch a file in
> | *nix).
> | > | But once people start using the file for sorts etc, then the thing
> gets
> | > | internally formatted exactly like any other data file would.
> | > |
> | > | So it's a data file, and it should get a dbf extension.
> | > |
> | > | Regards
> | > | HJR
> | > |
> | > |
> | >
> | >
> |
> |
>
>
Received on Thu Mar 25 2004 - 18:42:29 CST