Re: Doubt about Datapump - Compression

On Sun, 30 Dec 2007 05:26:12 -0800, lyxx09_at_gmail.com wrote:

> Hi All,
>
> I have been reading about the datapump and came to know about
> "compression"
> parameter.
>
> As per doc it will compress all the metadata before writing it out to
> the
> dump file. which is default.
>
> But I could not understand the benefit of this if this is just for
> metadata
> not the real data because metadata's size is just negligible as compare
> to whole database.
>
> Could you identify any other case where it is useful.
>
> Happy New Year 2008 !!
>
> Regards,
> Lyx

Happy New Year 2008. Oracle does support full compression, but only if you install what amounts to the latest patchset, according to D. Morgan. That latest patchset is called oracle11. Here is an exceprt from the utilities manual:

COMPRESSION Default: METADATA_ONLY

Purpose

Specifies which data to compress before writing to the dump file set.

Syntax and Description

COMPRESSION={ALL | DATA_ONLY | METADATA_ONLY | NONE}     *

      ALL enables compression for the entire export operation.     *

      DATA_ONLY results in all data being written to the dump file in compressed format.

    *

      METADATA_ONLY results in all metadata being written to the dump file in compressed format. This is the default.

    *

      NONE disables compression for the entire export operation.

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