The cost of a free feature

About twenty years ago, I was working on what would eventually become RavenDB, and I needed an engine to handle queries. Writing a query engine from scratch is its own very large project, quite separate from writing a database engine. I made a decision that I still consider one of the smartest I made in those early days: I built on top of Lucene as my indexing and query engine.That let me stand on a firm foundation while I dealt with the problems I actually cared about: building a NoSQL solution that didn't feel like juggling knives. Lucene gave me a mature, battle-tested way to index and query data, and I got to spend my time on the parts that made RavenDB RavenDB.It was a good decision. But like a lot of good decisions, it came with a bill attached, and the bill arrived about a decade later.Making use of features that are already there…Here is a query that every developer has written a thousand times: give me the ten most recent posts on my blog. You write those sorts of queries in…