indexes are simple
add_index :table_name, :column_name
or for multiple columns
add_index :table_name, [:column_name1, :column_name2, ...]
and to remove an index
remove_index :table_name, :column_name
in the case of a multi-column index, rails just uses the first column name to generate the index name, so in order to remove it, just provide the first column in the index
for creating foreign key relationships, it is also quite simple but there are no built-in rails methods for creating them. in self.up, after your create_table call, add
execute "alter table things add constraint fk_things_widget_id foreign key (widget_id) references widgets(id)"
and in self, down, before the drop_table call, add
execute "alter table things drop foreign key fk_things_widget_id"
Chris
