lock_command

lock_command 
      ::= 
      "lock" "table" 
      [ schema_name "." ] table_name [ "@" link_name ] 
      { "," [ schema_name "." ] table_name [ "@" link_name ] } 
      "in" lock_mode "mode" [ "nowait" ] 

[rule list]
This rule is call by

to_modify_data