On 2/22/07, Zeugswetter Andreas ADI SD <[EMAIL PROTECTED]> wrote:
> > I very much like Hannu's idea, but it does present some issues. > > > > > I too liked Hannu's idea initially, but Tom raised a valid > concern that it does not address the basic issue of root > tuples. According to the idea, a DEAD root tuple can be used > for a subsequent update of the same row. If you are reusing the existing slot of a root tuple how will that slot likely have room for an extra pointer and a live tuple ? If the idea does not cover root reuse we don't need pointers.
Hannu talked about using one of xmin/xmax for storing back-pointers. There were objections to that since it breaks the xmax/xmin matching robustness that we have today.
Imho we should follow the swing idea.
Yes, thats one option. Though given a choice I would waste four bytes in the heap-page than inserting a new index entry. The heap tuples can be vacuumed rather easily than the index entries which, if I am mistaken, can not be reused even after marked LP_DELETEd. Thanks, Pavan -- EnterpriseDB http://www.enterprisedb.com
