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Re: When should I use COMPRESSY on export?

From: Jerry Gitomer <jgitomer_at_erols.com>
Date: Thu, 09 Nov 2000 05:47:07 GMT
Message-ID: <20001109.5470700@mis.configured.host>

>>>>>>>>>>>>>>>>>> Original Message <<<<<<<<<<<<<<<<<<

On 11/8/00, 6:55:49 PM, carmen_at_fabgear.com (Carmen Iannacone) wrote regarding When should I use COMPRESS=Y on export?:

> I'm trying to migrate data from one database to another.
 

> I know that I have some chaining going on, so I need
> to recreate the tables via a script, and then import with
> IGNORE=Y. The question I have is whether the exports
> that I'm doing should be done with COMPRESS=Y.
 

> I'll be honest, I'm a little confused about that option; I
> thought I read somewhere that it may lead to a file that's
> not importable.
 

> But, I want to improve my physical layout and reduce
> some dynamic extension.
 

> Is this the time to use COMPRESS=Y, or should I
> in fact ALWAYS be using COMPRESS=Y?
 

> Also, if you've read this far, how can I guarantee that
> the versions of EXP and IMP are compatible. They're
> both in the 8.* family...
 

> Thanks for any help!
 

> Carmen
> (carmen_at_fabgear.com)

        My personal preference is to NEVER use compress=y.

        This is because I prefer to have uniform size extents (local tablespace s
under 8i)
so that I don't have to ever reorganize my tablespaces.

        The problem with using compress=y is that the entire table will be exported as a single extent. This in turn can lead to highly fragmented  

tablespaces with lots of unusable space or to situations in which you cannot import a table back into the same tablespace due to a lack of empty contiguous space. Received on Wed Nov 08 2000 - 23:47:07 CST

Original text of this message

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