diff options
| author | Michael Paquier | 2021-10-23 05:43:51 +0000 |
|---|---|---|
| committer | Michael Paquier | 2021-10-23 05:43:51 +0000 |
| commit | e6c5f1b452655a20b687b3e39d8eb816d8f8cbf7 (patch) | |
| tree | f6454e7a777dc2841bc5b19afe0772b4084b944c /doc/src | |
| parent | 871dfe4b7270aa33d0ed8c05abd59d3c2653bd1e (diff) | |
doc: Describe calculation method of streaming start for pg_receivewal
The documentation was imprecise about the starting LSN used for WAL
streaming if nothing can be found in the local archive directory
defined with the pg_receivewal command, so be more talkative on this
matter.
Extracted from a larger patch by the same author.
Author: Ronan Dunklau, Michael Paquier
Discussion: https://postgr.es/m/18708360.4lzOvYHigE@aivenronan
Backpatch-through: 10
Diffstat (limited to 'doc/src')
| -rw-r--r-- | doc/src/sgml/ref/pg_receivewal.sgml | 23 |
1 files changed, 23 insertions, 0 deletions
diff --git a/doc/src/sgml/ref/pg_receivewal.sgml b/doc/src/sgml/ref/pg_receivewal.sgml index 3f254f6e16b..9a4a03d1475 100644 --- a/doc/src/sgml/ref/pg_receivewal.sgml +++ b/doc/src/sgml/ref/pg_receivewal.sgml @@ -77,6 +77,29 @@ PostgreSQL documentation </para> <para> + The starting point of the write-ahead log streaming is calculated when + <application>pg_receivewal</application> starts: + <orderedlist> + <listitem> + <para> + First, scan the directory where the WAL segment files are written and + find the newest completed segment file, using as starting point the + beginning of the next WAL segment file. This is calculated independently + on the compression method used to compress each segment. + </para> + </listitem> + + <listitem> + <para> + If a starting point cannot be calculated with the previous method, + the latest WAL flush location is used as reported by the server from + a <literal>IDENTIFY_SYSTEM</literal> command. + </para> + </listitem> + </orderedlist> + </para> + + <para> If the connection is lost, or if it cannot be initially established, with a non-fatal error, <application>pg_receivewal</application> will retry the connection indefinitely, and reestablish streaming as soon |