The similar documents discovery pattern is common and useful. Google has it in search results "Pages similar to these", Spotify has it in its app "Radio based on this", Amazon has it on every product page "list of related products". Is there any function in Google App Engine Search API that captures this, such as
document.fetch_similar(6,exclude_field=["id","name"])
If so where to find it, if not how to do so scalably in an i18n environment in Google App Engine?
The Full Text Search api does not have this feature. You would need to implement your own behaviour to achieve this, which generally makes sense because 'similarity' is a domain specific problem. It also does not have any 'like' feature, beyond the ~ operator.