On 24.03.20 19:46, Robert Haas wrote:
Do we use shared_buffers for WAL ?
No.
What's about the explanation in https://www.postgresql.org/docs/12/runtime-config-wal.html : "wal_buffers (integer) The amount of shared memory used for WAL data that has not yet been written to disk. The default setting of -1 selects a size equal to 1/32nd (about 3%) of shared_buffers, ... " ? My understanding was, that the parameter wal_buffers grabs some of the existing shared_buffers for its own purpose. Is this a misinterpretation? Are shared_buffers and wal_buffers two different shared memory areas?
Kind regards, Jürgen