Re: decoupling table and index vacuum

On Thu, Feb 10, 2022 at 3:10 AM Dilip Kumar <dilipbalaut@gmail.com> wrote:
> Actually I was not worried about the scan getting slow.  What I was
> worried about is if we keep ignoring the dead tuples for long time
> then in the worst case if we have huge number of dead tuples in the
> index maybe 80% to 90% and then suddenly if we get a lot of insertion
> for the keys which can not use bottom up deletion (due to the key
> range).  So now we have a lot of pages which have only dead tuples but
> we will still allocate new pages because we ignored the dead tuple %
> and did not vacuum for a long time.

It seems like a reasonable concern to me ... and I think it's somewhat
related to my comments about trying to distinguish which dead tuples
matter vs. which don't.

-- 
Robert Haas
EDB: http://www.enterprisedb.com