docs: Improve the description of num_timed column in pg_stat_checkpointer.

MasaoFujii · MasaoFujii · commit fa3a022136fc · 2024-09-19T02:16:00.000+09:00
The previous documentation stated that num_timed reflects the number of scheduled checkpoints performed. However, checkpoints may be skipped if the server has been idle, and num_timed counts both skipped and completed checkpoints. This commit clarifies the description to make it clear that the counter includes both skipped and completed checkpoints. Back-patch to v17 where pg_stat_checkpointer was added. Author: Fujii Masao Reviewed-by: Alexander Korotkov Discussion: https://postgr.es/m/9ea77f40-818d-4841-9dee-158ac8f6e690@oss.nttdata.com
diff --git a/doc/src/sgml/monitoring.sgml b/doc/src/sgml/monitoring.sgml
@@ -2978,7 +2978,10 @@ description | Waiting for a newly initialized WAL file to reach durable storage
        <structfield>num_timed</structfield> <type>bigint</type>
       </para>
       <para>
-       Number of scheduled checkpoints that have been performed
+       Number of scheduled checkpoints due to timeout.
+       Note that checkpoints may be skipped if the server has been idle
+       since the last one, and this value counts both completed and
+       skipped checkpoints
       </para></entry>
      </row>
 
