RE: Freeing Deleted Disk Space

["Chris Devous" <cdevous@xxxxxxxxxxx>]

Buck's advice can result in enhanced performance, particularly if an 
application tends
to access a large file by a specific sequence, like an order entry program 
would tend
to do an order lines file by order/line.

One caveat:  The if the access path named in KEYFILE is a logical view, it can 
not
have select/omit sequences.

--Chris

>
> Scotty Muir wrote:
>
> >We have a file (*File PF-Data) on the AS/400
> >that one of our programmer has deleted a
> >lot of records from, but we have not gotten
> >back any of the freed disk space.
>
>
>  Buck wrote:
>
> There have been several mentions of RGZPFM and the fact that nobody else can
> be using the file whilst you reorg it, but nobody has mentioned the KEYFILE
> parameter.  It might be a can of worms for an AS/400 newcomer and no harm
> will come if you disregard the following...
>
> RGZPFM allows you to physically re-sort the records according to the
> sequence of the file specified in the KEYFILE parameter.  If you have an
> item master file (PF) which is keyed in item number order AND you do most of
> your read/chains by item number you may see a performance boost if you
> specified KEYFILE(*FILE).  If most of your read/chains are by vendor, and
> logical file PRODLF1 is the logical ordered by vendor ID, then
> KEYFILE(PRODLF1) will sort the PF in vendor ID order.
>
> No harm will come from omitting this, but you could conceivably hurt
> performance if you pick a key sequence that is rarely used.  I thought I'd
> bring this up to give you something more to think about.
>   --buck