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. -- Álvaro Herrera https://www.2ndQuadrant.com/ PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services
