Re: Autovacuum degrades all other operations by keeping all buffersdirty?

On 2018-Aug-31, David Pacheco wrote:

> From reading the 9.6.3 source, it looks like the autovacuum process
> itself is single-threaded, and it reads pages essentially linearly
> from the relation (possibly skipping some).  When the autovacuum
> process needs to modify a page, it doesn't write it directly, but
> rather marks the buffer dirty.  The page will be written later,

Unless there's some bug, there is a BufferAccessStrategy that only lets
a few dozen buffers go unwritten before the autovac worker process
itself is forced to write some.

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