+corresponds to \(dqnews_locations\(dq.
+.P
+To relate the two, a third table may exist with name
+<parent>__<child>. Note the two underscores. This prevents ambiguity
+when the child table itself contains underscores. The table joining
+\(dqnews\(dq with \(dqnews_locations\(dq is thus called
+\(dqnews__news_locations\(dq. This is necessary when the child table
+has a unique constraint; we don't want to blindly insert duplicate
+records keyed to the parent. Instead we'd like to use the third table
+to map an existing child to the new parent.
+.P
+Where it makes sense, children are kept unique to prevent pointless
+duplication. This slows down inserts, and speeds up reads (which are
+much more frequent). There is a tradeoff to be made, however. For a
+table with a small, fixed upper bound on the number of rows (like
+\(dqodds_casinos\(dq), there is great benefit to de-duplication. The
+total number of rows stays small, so inserts are still quick, and many
+duplicate rows are eliminated.