Elasticsearch is probably not needed, but a full-text index based search engine - plain vanilla Java Lucene or CLucene - could be very useful, and indeed be mor

Elasticsearch is probably not needed, but a full-text index based search engine - plain vanilla Java Lucene or CLucene - could be very useful, and indeed be more appropriate given that the notes are unstructured text (I actually don't see the need for SQL unless you need to perform very complex operations on the structured meta-data). The advantage is an easy-to-learn search syntax that is flexible and similar to Google: https://lucene.apache.org/core/2_9_4/queryparsersyntax.html https://lucene.apache.org/core/2_9_4/queryparsersyntax.html In addition to a document field for your notes, you can manage and query any number of meta-data fields e.g. Tom M* birthday:July retrieves all notes that mention Tom with a last name starting with "M" as long as the notes also have a meta-data field called birthday where the value must be July. (Try compare doing this with the SQL equivalent version of the query!)