Thinking Sphinx delta indexing - delta index not getting updated

I have delta indexing setup for thinking sphinx on one of my models. When ever a record gets updated, the delta is being set to True, but I don't see the index getting updated with the changes made 开发者_JAVA技巧to the record. I have my sphinx configuration files updated with the delta property changes. Any idea why the delta indexing is not getting triggered?

According to the documentation after you update the database and the model, you should do this:

rake thinking_sphinx:rebuild

Maybe you've omit that step..