Re: Decent VACUUM (was: Buglist)

Manfred Koizar wrote:
> [ still brainstorming ... ]
>
> On Thu, 21 Aug 2003 17:16:50 -0400, Tom Lane <tgl@sss.pgh.pa.us>
> wrote:
> >> Whenever a backend encounters a dead tuple it inserts a reference to
> >> its page into the RSM.
> >
> >This assumes that backends will visit dead tuples with significant
> >probability.  I doubt that assumption is tenable;
>
> Good point.  What about:  Whenever a backend *deletes* a tuple it
> inserts a reference to its page into the RSM?  Then an entry in the
> RSM doesn't necessarily mean that the referenced page has reclaimable
> space, but it would still be valueable information.

Added to TODO:

    * Maintain a map of recently-expired of pages so vacuum can reclaim
      free space without a sequential scan

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