Re: [HACKERS] Patch: Write Amplification Reduction Method (WARM)

Bruce Momjian wrote:

> Well, let's walk through this.  Let's suppose you have three updates
> that stay on the same page and don't update any indexed columns --- that
> would produce a HOT chain of four tuples.  If you then do an update that
> changes an indexed column, prior to this patch, you get a normal update,
> and more HOT updates can be added to this.  With WARM, we can join those
> chains

With WARM, what happens is that the first three updates are HOT updates
just like currently, and the fourth one is a WARM update.

> and potentially trim the first HOT chain as those tuples become
> invisible.

That can already happen even without WARM, no?

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Álvaro Herrera                https://www.2ndQuadrant.com/
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