RE: Single level store & record blocking on update files (was RE:Where is IBM?)

[Dan <dbcemid@xxxxxxxxx>]

Mike,

Thanks for the reply, but I'm not sure I understand your point.  The S/36 
allowed record blocking
in memory for an update file, and even allowed double buffering in lowly 
RPG-II.  If you blocked
200 records, and you updated those 200 records without accessing any other 
records in the file,
and updated them multiple times, all of that updating took place in memory.  
The disk didn't see
it until either a request for a record outside of the block took place, or the 
program ended.  I
benchmarked it and proved it.

On the AS/400, there is no record blocking for update files, period.  I fail to 
see why this is,
especially in light of the AS/400's single level store.

- Dan

--- Mike Shaw <mhshaw@xxxxxxxxxxxxxxxx> wrote:
> Dan,
> 
> This is because all storage on the iSeries, whether it be main storage
> (memory) or auxiliary storage (disk) is addressed as if it were ALL
> residing in main storage.  This even goes back to the System/38 days.
> 
> Dr. Frank Solits' books "Inside the AS/400" and "Fortress Rochester"
> does a great job of explaining this in very simple terms.
> 
> Yup, it's a virtual machine!  :-)
> 
> Regards,
> 
> Mike Shaw

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