sl_listenIndicates how nodes listen to events from other nodes in the Slony-I network.
Structure of sl_listen
li_origininteger PRIMARY KEY REFERENCES sl_node
The ID # (from sl_node.no_id) of the node this listener is operating on
li_providerinteger PRIMARY KEY REFERENCES sl_path
The ID # (from sl_node.no_id) of the source node for this listening event
li_receiverinteger PRIMARY KEY REFERENCES sl_path
The ID # (from sl_node.no_id) of the target node for this listening event