Hello Ann:

As I understand it when a record is deleted a new primary version with a
mark (a flag) is put on it indicating that fact and the previous version of
the record is copied on another location (same page if there is room or
another page if there is not)

Is that true?

Greetings.

Walter.

On Thu, May 2, 2013 at 1:55 PM, Ann Harrison <aharrison@...>wrote:

> **
>
>
> On Thu, May 2, 2013 at 11:11 AM, Ivan Přenosil <Ivan.Prenosil@...
> >wrote:
>
> Many things that are very true and valuable. I would like to clarify one
> thing:
>
>
> >
> > The problem is that UPDATE will never change
> >
> > record's location, it will stay on "it's" page "forever".
> >
> >
> That is absolutely true, but possibly misleading to the naive. Every
> record
> has a "primary version" which is the most recently created version. When
> you
> store a record, the primary version goes on a data page. That data page
> will
> always hold the primary record version, no matter how many times the record
> is modified - that's the "home page" for that record. Each modification
> creates
> a new primary record version, which must be on the record's home page. If
> there's room on the page for a second version, fine. If not, Firebird moves
> the
> older version to a different page and puts the new version on the reclaimed
> space on the home page.
>
> Good luck,
>
> Ann
>
>
> [Non-text portions of this message have been removed]
>
>
>


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