[轉]database.yml &, <<, *
http://stackoverflow.com/questions/6651275/what-do-the-mean-in-this-database-yml-file The & marks an alias for the node (in your example &defaultaliases the development node as “default”) references the aliased node with the name “default”. «: inserts the content of that node. test: &test «: *default default_env: «: *production