Re: Buffering and single level store (was RE: chain problem)

["Keith Carpenter" <CarpCon@xxxxxxx>]

John Sears once explained that one of reasons IBM went with SLS on the S/38
was to be able to take advantage of new storage technologies that were
promising at the time ( bubble memory ).  Had bubble memory not been the big
bust it was, DASD could have become obsolete.


----- Original Message ----- 
From: "DeLong, Eric" <EDeLong@xxxxxxxxxxxxxxx>

> Regarding buffering and SLS, my understanding of this is that SLS is just
a
> big memory map that encompases all storage within the box.  The fact that
a
> database file is associated with a particular memory address does not
impart
> any real performance benefit.... It just makes the management of those
> resources simpler.  When you access a file that is stored on DASD, the OS
> must still copy that data from the device into main storage.  From main
> storage, then, it gets sent to the application in discreet chunks.  Record
> blocking sends larger chunks, saving on overhead.