Re: Free space management within heap page

Pavan Deolasee wrote:
> One assumption I am  making here is that its sufficient to mark the line
> pointer
> "unused" (reset LP_USED flag) even though there is an index entry pointing
> to
> the tuple. During index scan, we anyways check for ItemIdIsUsed() before
> proceeding further. I know it might break the ctid chain, but does that
> really
> matter ? I don't see any reason why somebody would need to follow ctid 
> chain
> past a dead tuple.

You can't clear the LP_USED flag, but you could use the LP_DELETE flag 
that's currently not used in heap pages.

--   Heikki Linnakangas  EnterpriseDB   http://www.enterprisedb.com