So, you've got these two search engines in RavenDB - Lucene and Corax right? Here's how you can tell RavenDB which one you want to use:

The easiest way in code would be something like this:

{
    public YourIndex()
    {
        // Just tell it straight up which engine you want to use
        SearchEngineType = Raven.Client.Documents.Indexes.SearchEngineType.Lucene;
        
        // That's it! Simple as that
    }
}

But here's the thing - you've got options!

1. You can set it right in your code (like shown above)
2. You can click around in the RavenDB Studio if you're more of a visual person
3. Or you can edit the settings.json file if you're old school

I totally get that you might have some complex indexes that aren't ready for Corax yet - no worries! That's actually super common. My friendly advice? Start with explicitly setting Lucene for those complex indexes in your code, keeps everything stable while you figure out your next move.

Need me to clarify anything? I'm here to help!