pg_on_connection_loss dbHandle callbackCommand
pg_on_connection_loss creates,
changes, or cancels a request to execute a callback command if an
unexpected loss of connection to the database occurs. With a
callbackCommand parameter, the
request is established, or the command string of an already
existing request is replaced. With no callbackCommand parameter, a prior request is
canceled.
The callback command string is executed from the Tcl idle
loop. That is the normal idle state of an application written
with Tk. In non-Tk Tcl shells, you can execute update or vwait
to cause the idle loop to be entered.