RE: reorg HUGE file

["Al Barsa, Jr." <barsa2@xxxxxxxxxxxxxxxxxxx>]

At 01:51 PM 2/27/01 +0100, you wrote:
>Al wrote:
>
> > > If I did a RGZPFM, I'd remove the members from the file's logicals
>before
>..
> > Clearly this will have positive performance implications if you have any
> > multi-record format logicals, or LF joins.
>
>Why?
>In all practical context I have found that
>   o  Multi-record format logicals are the same as old RPF Matching record
>   o  LF join is the same as RPG CHAIN
>except of cause that it's more fool-proof and needs less coding
>In other words: Theese two constructions have the overhead connected to
>the access time (millisecond), rather than to the build/maintain time

Because there will be seize/lock contention on two files 
simultaneously.  By removing them first, particularly if you were reorging 
multiple files in one pass (multiple executions of the RGZPFM) command, you 
could minimize additional locking.  We did some benchmarking of this late 
in the life of the System/38 CPF R08M01, PC F, and proved this 
conclusively.  The files were clearly much smaller then, but then again was 
both the CPU speed and the DASD speed.

Al




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