diff options
| author | Michael Paquier <michael@paquier.xyz> | 2020-02-06 09:18:06 +0900 |
|---|---|---|
| committer | Michael Paquier <michael@paquier.xyz> | 2020-02-06 09:18:06 +0900 |
| commit | b025f32e0b5d7668daec9bfa957edf3599f4baa8 (patch) | |
| tree | f0bf150285ba5f704826db1910c675b63a9a1ff2 /doc/src | |
| parent | bf6cc19e347d4cb8dfc8f05a59171ac06e18b5e5 (diff) | |
Add leader_pid to pg_stat_activity
This new field tracks the PID of the group leader used with parallel
query. For parallel workers and the leader, the value is set to the
PID of the group leader. So, for the group leader, the value is the
same as its own PID. Note that this reflects what PGPROC stores in
shared memory, so as leader_pid is NULL if a backend has never been
involved in parallel query. If the backend is using parallel query or
has used it at least once, the value is set until the backend exits.
Author: Julien Rouhaud
Reviewed-by: Sergei Kornilov, Guillaume Lelarge, Michael Paquier, Tomas
Vondra
Discussion: https://postgr.es/m/CAOBaU_Yy5bt0vTPZ2_LUM6cUcGeqmYNoJ8-Rgto+c2+w3defYA@mail.gmail.com
Diffstat (limited to 'doc/src')
| -rw-r--r-- | doc/src/sgml/monitoring.sgml | 12 |
1 files changed, 12 insertions, 0 deletions
diff --git a/doc/src/sgml/monitoring.sgml b/doc/src/sgml/monitoring.sgml index 8839699079f..08353cb3434 100644 --- a/doc/src/sgml/monitoring.sgml +++ b/doc/src/sgml/monitoring.sgml @@ -623,6 +623,18 @@ postgres 27093 0.0 0.0 30096 2752 ? Ss 11:34 0:00 postgres: ser <entry>Process ID of this backend</entry> </row> <row> + <entry><structfield>leader_pid</structfield></entry> + <entry><type>integer</type></entry> + <entry> + Process ID of the parallel group leader if this process is or + has been involved in parallel query, or null. This field is set + when a process wants to cooperate with parallel workers, and + remains set as long as the process exists. For a parallel group leader, + this field is set to its own process ID. For a parallel worker, + this field is set to the process ID of the parallel group leader. + </entry> + </row> + <row> <entry><structfield>usesysid</structfield></entry> <entry><type>oid</type></entry> <entry>OID of the user logged into this backend</entry> |