查询状态为 时是什么意思null
?
my_database_name> SELECT pid, datname, usename, application_name, query_start, state, state_change FROM pg_stat_activity;
+-------+------------------+------------------+--------------------------+-------------------------------+---------+-------------------------------+
| pid | datname | usename | application_name | query_start | state | state_change |
|-------+------------------+------------------+--------------------------+-------------------------------+---------+-------------------------------|
| 19093 | my_database_name | my_user_nam | pgcli | 2020-02-07 12:58:54.665447+00 | active | 2020-02-07 12:58:54.665449+00 |
| 13777 | my_database_name | some_other_user | DBeaver 6.3.2 - Main | <null> | <null> | <null> |
| 13776 | my_database_name | some_other_user | DBeaver 6.3.2 - Metadata | <null> | <null> | <null> |
| 2036 | <null> | <null> | | <null> | <null> | <null> |
+-------+------------------+------------------+--------------------------+-------------------------------+---------+-------------------------------+