Lucene really does feel like magic sometimes. It was designed expressly to solve the top K problem at hyper scale. It's incredibly mature technology. You can go from zero to a billion documents without thinking too
much about anything other than the amount of mass storage you have available.
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.
jmgimenotoday at 7:16 AM
Maybe I'm wrong, but for this query:
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.
davidelettieritoday at 6:35 AM
The "But Wait, We Need Filters Too" paragraph mentions "US" filter which is introduced only later on.
h1fratoday at 9:41 AM
Postgres is really good at a lot of things, but it's very unfortunate that it's really bad at simple analytics. I wish there was a plugin instead of having to have N databases
Vadim_samokhintoday at 8:31 AM
Just in case, there is a btree_gin extension which can be used in queries combining gin-indexable column and btree-indexable column. It doesnβt solve top-K ordering problem though.
JEONSEWONtoday at 5:51 AM
[flagged]
bbshfishetoday at 6:50 AM
[dead]
taconetoday at 7:24 AM
The issue here is the row based format. You simply can't filter on arbitrary columns with that. Either use an external warehouse or a columnar plug-in like Timescale.