Обсуждение: WAL compression and replica
If WAL compression is enabled, does this mean that traffic to a file-based WAL-shipping standby is compressed? (In otherwords, WAL files are sent post-compression?) -- Scott Ribe scott_ribe@elevated-dev.com https://www.linkedin.com/in/scottribe/
On Mon, Mar 25, 2024 at 1:10 PM Scott Ribe <scott_ribe@elevated-dev.com> wrote:
If WAL compression is enabled, does this mean that traffic to a file-based WAL-shipping standby is compressed? (In other words, WAL files are sent post-compression?)
From the docs:
When enabled, the PostgreSQL server compresses full page images written to WAL when full_page_writes is on or during a base backup.
That is, some of the contents are compressed, it is not the container that gets compressed. That is always 64MB in a default compilation.
David J.
> On Mar 25, 2024, at 2:17 PM, David G. Johnston <david.g.johnston@gmail.com> wrote: > > On Mon, Mar 25, 2024 at 1:10 PM Scott Ribe <scott_ribe@elevated-dev.com> wrote: > If WAL compression is enabled, does this mean that traffic to a file-based WAL-shipping standby is compressed? (In otherwords, WAL files are sent post-compression?) > > From the docs: > When enabled, the PostgreSQL server compresses full page images written to WAL when full_page_writes is on or during abase backup. > > That is, some of the contents are compressed, it is not the container that gets compressed. That is always 64MB in a defaultcompilation. > > David J. I read that last week, and totally missed the implication. Thanks.