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From Bryan Pendleton <bpendle...@amberpoint.com>
Subject Re: INPLACE Table Compression
Date Tue, 27 Mar 2007 15:41:54 GMT
> “Inplace” Compression utility, no disk space is recovered and the size 
> of the “*.dat” files is not reduced.

That is correct. In-place compression re-arranges the records on
the existing pages of the existing file, gathering the existing
records together and shifting all the free space to be together.
This makes access to the existing records more efficient, and
allows new records to efficiently make use of the available free
space, but does nothing to reduce the overall size of the file.

Think of it as somewhat similar to the "defragment" process that
your operating system offers. Your overall disk volume is still
the same size, but the use of the disk is improved.

To release disk space back to the operating system, you must use
the version of compression which copies the data to a new file,
then deletes the old file.

thanks,

bryan


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