pg_stat_activity.query empty

[Robert Lichtenberger]

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