Gbase 8C server signal function

The server signal function sends control signals to other server processes . Only system administrators can use these functions .

pg_cancel_backend(pid int)

describe ： Cancel the current query of a backend .

return type ：Boolean

remarks ：pg_cancel_backend Go from pid The identified backend process sends a query to cancel （SIGINT） The signal . Of an active backend process PID It can be downloaded from pg_stat_activity View's pid Field found , Or use it on the server ps List database processes . have SYSADMIN Privileged user , The owner of the database to which the backend process is connected , The owner of the back-end process or inherits the built-in role gs_role_signal_backend Users with permission have the right to use this function .

pg_reload_conf()

describe ： Cause all server processes to reload their configuration files （ System administrator role is required ）.

return type ：Boolean

remarks ：pg_reload_conf Send a... To the server SIGHUP The signal , Cause all server processes to reload configuration files .

pg_rotate_logfile()

describe ： Scroll the log files of the server （ System administrator role is required ）.

return type ：Boolean

remarks ：pg_rotate_logfile Send a signal to the log file manager , Tell it to switch to a new output file immediately . This function can only be used in redirect_stderr It is only useful for log output , Otherwise, there is no log file manager subprocess .

pg_terminate_backend(pid int)

describe ： Terminate a background thread .

return type ：Boolean

remarks ： If it works , The function returns true, Otherwise return to false. have SYSADMIN Privileged user , The owner of the database to which the backend process is connected , The owner of the back-end process or inherits the built-in role gs_role_signal_backend Users with permission have the right to use this function .

Example ：

 gbase=# SELECT pid from pg_stat_activity;

       pid

-----------------

 140573611915008

 140573668599552

 140574052771584

 140573954000640

 140574121588480

 140574004344576

 140573970781952

 140573987563264

(8 rows)

    

gbase=# SELECT pg_terminate_backend(140573987563264);

 pg_terminate_backend

----------------------

 t

(1 row)

pg_terminate_session(pid int64, sessionid int64)

describe ： Terminate a background session.

return type ：Boolean

remarks ： If it works , The function returns true, Otherwise return to false. have SYSADMIN Privileged user , The owner of the database to which the session is connected , The owner of the session or inherits the built-in role gs_role_signal_backend Users with permission have the right to use this function .