Jeffrey L. Taylor wrote in post #960038: > Quoting Marnen Laibow-Koser <[email protected]>: >> > of >> >> Composite *primary keys* are not (but there's a plugin). Composite >> *indices* are. You can specify multiple columns in add_index. >> > > Sorry I left out a constraint that turned out to be critical. This is > the > primary and only index on this table. I've tried the plug-in. It was > not > reliable in my use scenario.
Then here's what I would suggest. Keep the composite index, but do not make it the primary key. Use a surrogate key (that is, a Rails-style id field) instead. You'll be happier. Rails will be happier. Composite primary keys tend to be annoying (yes, I've worked with them successfully, but I'm glad I no longer have to), and anyway surrogate keys are nicer because you can guarantee that they'll never ever change over the life of the record. > >> >> > And I will not switch >> > DB >> > servers next week, so having the index creation in portable form is not >> > a necessity. >> >> Never write SQL in Rails unless there's no other way. >> > > If it is feasible in Rails, I do it that way. However, I was explicitly > lifting the constraint of doable in Rails for this usecase. If the > usecase > included dozens of servers and multiple DB server software, then staying > in > Rails would make sense. I have one production server (with test > database) and > one or two development setups (with test databases). Setup in the > database > client program is very doable. But it's a bad idea since it defeats automation. The right way to do this -- if you *must* -- is to put raw SQL in the migration and set the schema dumper to use SQL. That way you can still use migrations and the schema file. > Fighting to shoehorn a usecase that > Rails does > not handle into Rails is not productive. On the contrary, it's very productive. That's how many of the best Rails plugins got developed. But in this case, all you need to do is add a surrogate key. > > Jeffrey Best, -- Marnen Laibow-Koser http://www.marnen.org [email protected] -- Posted via http://www.ruby-forum.com/. -- You received this message because you are subscribed to the Google Groups "Ruby on Rails: Talk" group. To post to this group, send email to [email protected]. To unsubscribe from this group, send email to [email protected]. For more options, visit this group at http://groups.google.com/group/rubyonrails-talk?hl=en.
