Every time I've used Lucene I have combined it with a SQL provider. It's not necessarily about one or the other. The FTS facilities within the various SQL providers are convenient, but not as capable by comparison. I don't think mixing these into the same thing makes sense. They are two very different animals that are better joined by way of the document ids.
SELECT * FROM benchmark_logs WHERE severity < 3 ORDER BY timestamp DESC LIMIT 10;
this index
CREATE INDEX ON benchmark_logs (severity, timestamp);
cannot be used as proposed: "Postgres can jump directly to the portion of the tree matching severity < 3 and then walk the timestamps in descending order to get the top K rows."
Postgres with this index can walk to a part of the tree with severity < 3, but timestamps are sorted only for the same severity.
If latency really matters and you are working with large datasets, columnar extensions help, but they come with operational overhead and can limit transactional features, so it's usually better to stick with row-based unless you have a clear need.
