Re: Piping Exports (Unix)

In <50700_at_seismo.CSS.GOV>, I wrote:
> Our database filled up and we ran out of disk space for exports. I stumbled
> on the following that seems to work on DEC RISC and SUN 4 database hosts (the
> version of exp is 6.0.33.2.2 on both systems):
>
> exp user/account file=stdout | compress > expdat.dmp.Z
> ^^^^^^
> This produces a compressed file called "expdat.dmp.Z" that is 28-30% the
> size of the uncompressed export file.
>
> Does anybody know of any reason that exports should *not* be piped like this?

One of the main problems with my method, besides counting on an undocumented feature :-), was the import didn't work via a pipe on the DEC. I received a much more sensible tip that works reliably both ways:

    I have found that the best way to do this is using Unix's named-pipes     feature. Simply:

    % mknod /tmp/compresspipe p
    % compress -c </tmp/compresspipe>/backup/oraexp/exp1MAY92.dmp &
    % exp system/manager full=y ..... file=/tmp/compresspipe

    Voila! After the compress receives an EOF (sent by exp), it     terminates, leaving a nice compressed file. This saves using various     undocumented features (as file=stdout must be?!)

    To import, do the same thing:

    % uncompress -c </backup/oraexp/exp1MAY92.dmp >/tmp/compresspipe &     % imp system/manager .... file=/tmp/compresspipe

I tried this for both export and import on SUN 4 and DEC RISC and had no problems. On the SUN 4 I still get a final message "Import terminated successfully with warnings." when, in fact, no warnings have been output. But everything looks good.

My thanks to everybody who responded,

• jean

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