Thread: pg_stat_activity.query empty
When executing "SELECT * FROM pg_stat_activity" I get lots of rows that have an empty "query" column. According to [1] this column should contain the "Text of this backend's most recent query", either a query that is currently running or the last query that was executed. So how comes that a lot of the rows in pg_stat_activity have an empty "query"? https://www.postgresql.org/docs/current/monitoring-stats.html#MONITORING-PG-STAT-ACTIVITY-VIEW
On Tue, Apr 26, 2022 at 6:55 AM Robert Lichtenberger <r.lichtenberger@synedra.com> wrote:
When executing "SELECT * FROM pg_stat_activity" I get lots of rows that
have an empty "query" column.
According to [1] this column should contain the "Text of this backend's
most recent query", either a query that is currently running or the last
query that was executed.
So how comes that a lot of the rows in pg_stat_activity have an empty
"query"?
https://www.postgresql.org/docs/current/monitoring-stats.html#MONITORING-PG-STAT-ACTIVITY-VIEW
They've never executed a query. Probably due to connection pooling opening connections for the pool but never needing to hand them out.
David J.
On Tue, 2022-04-26 at 06:59 -0700, David G. Johnston wrote: > On Tue, Apr 26, 2022 at 6:55 AM Robert Lichtenberger <r.lichtenberger@synedra.com> wrote: > > When executing "SELECT * FROM pg_stat_activity" I get lots of rows that > > have an empty "query" column. > > > > According to [1] this column should contain the "Text of this backend's > > most recent query", either a query that is currently running or the last > > query that was executed. > > > > So how comes that a lot of the rows in pg_stat_activity have an empty > > "query"? > > > > https://www.postgresql.org/docs/current/monitoring-stats.html#MONITORING-PG-STAT-ACTIVITY-VIEW > > They've never executed a query. Probably due to connection pooling opening connections for the pool but never needingto hand them out. An alternative option is that the last query sent was an empty string. Yours, Laurenz Albe
2022年4月26日(火) 23:24 Laurenz Albe <laurenz.albe@cybertec.at>: > > On Tue, 2022-04-26 at 06:59 -0700, David G. Johnston wrote: > > On Tue, Apr 26, 2022 at 6:55 AM Robert Lichtenberger <r.lichtenberger@synedra.com> wrote: > > > When executing "SELECT * FROM pg_stat_activity" I get lots of rows that > > > have an empty "query" column. > > > > > > According to [1] this column should contain the "Text of this backend's > > > most recent query", either a query that is currently running or the last > > > query that was executed. > > > > > > So how comes that a lot of the rows in pg_stat_activity have an empty > > > "query"? > > > > > > https://www.postgresql.org/docs/current/monitoring-stats.html#MONITORING-PG-STAT-ACTIVITY-VIEW > > > > They've never executed a query. Probably due to connection pooling opening connections for the pool but never needingto hand them out. > > An alternative option is that the last query sent was an empty string. Or it's the kind of backend which doesn't normally execute queries. epp=# SELECT backend_type FROM pg_stat_activity WHERE query = ''; backend_type ------------------------------ autovacuum launcher pglogical supervisor logical replication launcher pglogical manager 16389 background writer checkpointer walwriter (7 rows) Regards Ian Barwick -- EnterpriseDB: https://www.enterprisedb.com