Add single document to search engine

I have a program where the users do frequent updates and/or additions to sql records. The program uses keyword to exclusively find data. I have a schedule that every five minutes I initiate an incremental indexing for the updated sql data. The problem is how do I search on the data that was added between scheduled indexing?
Is there a way to add just one document to the text search so that a new document that is created in sql can be search for.

Thank you,
Kevin