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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