Re: Open issues for HOT patch

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Tom Lane wrote:
> I wrote:
>> * The patch makes undocumented changes that cause autovacuum's decisions
>> to be driven by total estimated dead space rather than total number of
>> dead tuples.  Do we like this?

> If we do this, then it's not clear that having pgstats track dead space
> is worth the trouble at all.  It might possibly be of value for testing
> purposes to see how well pruning is doing, but I'm unconvinced that it's
> worth bloating stats messages and files to have this number in a
> production system.  An alternative that would serve as well for testing
> would be to teach contrib/pgstattuple to measure dead space.

As a DBA, I can say it doesn't really matter to me *how we track* the
dead space, as long as tracking it is:

1. Clear
2. Simple
3. Available by default (thus pgstattuple needs to push into core)


Sincerely,

Joshua D. Drake



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