Correction:  !!! I was wrong  !!!
The change I'm describing is something we're thinking about. The change
you're talking about pertains to keeping XM from having to scan all of the
virtual address of a file to find the dirty pages which need to be written
out during a checkpoint. Its optional because there is a feeling that some
third party tools may not call XM when they change some part of image data and
by searching for pages we find them all but since we will not look through
some part of the file we might miss something??? It did have a small
improvement in a very heavly loaded benchmark environment(700 users banging)
away against a single Database).

Of course if someone was modifying data in a database without calling XM
the database would not be consistent until after the checkpoint anyway...



: --
:          ___
:         /  /            Stephen F. Macsisak :Performance Consultant
: HEWLETT/hp/PACKARD      Commercial Systems Division
:       /__/              [log in to unmask] :(408)447-5851 (or MOONEY N201PC)

--
         ___
        /  /            Stephen F. Macsisak :Performance Consultant
HEWLETT/hp/PACKARD      Commercial Systems Division
      /__/              [log in to unmask] :(408)447-5851 (or MOONEY N201PC)