On a side note, what tools that leverage Datalog are in use by the HN crowd?

I know that Datomic[0] is very popular. I've also been playing with Clingo[1] lately.

blurbleblurble 2 days ago | parent | next [-]

Check out CozoDB, the embedded datalog-queried hybrid relational+vector+graph database written in Rust: https://www.cozodb.org/

I used it in a toy application and it was awesome.

This appears to be a dream database from the future.

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huevosabio 2 days ago | parent [-]

It seems like the project has been abandoned? Last commit a year ago.

	▲	anonzzzies 2 days ago \| parent [-]
		Yep, bit of a shame, many nice things in it and interesting to learn from but not active.

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embedding-shape 2 days ago | parent | prev | next [-]

I have some local-first/client-side applications using datascript in ClojureScript. Used datahike (FOSS Datomic alternative) some times on the backend too, but mostly tend to use XTDB nowadays, which used to have a Datalog API but I think they removed in favor of SQL-like way instead, which was kind of a shame.

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manoDev 2 days ago | parent [-]

I guess SQL is a requirement if they want to market their technology to normies.

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zozbot234 2 days ago | parent [-]

SQL can express Datalog-like queries rather easily using recursive CTE's, and even more so via the recently-added Property Graph Query syntax.

	▲	jitl 2 days ago \| parent [-]
		recursive CTEs suck usability-wise compared to the usual Datalog horn clause syntax. I won't speak to usability of the "datomic" kind of datalog though, that thing I haven't been able to wrap my head around.

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arxanas a day ago | parent | prev | next [-]

Just gave a talk about this: https://blog.waleedkhan.name/what-if-sql-were-good/

- Recommend Ascent (Rust only, but supports targeting WASM)

- Soufflé: good, but too hard to integrate into existing systems; lots of ergonomic problems in comparison to Ascent (can elaborate)

- CozoDB: really cool but seems to be abandoned

- Logica: have not tried it yet

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themk a day ago | parent [-]

Would like to hear about the ergonomic problems you have with souffle. We integrate it into our rust tools quite well, and generate typesafe rust bindings to our souffle programs, allowing us to insert facts and iterate over outputs.

	▲	arxanas 9 hours ago \| parent [-]
		It's quite possible that I have different, smaller-scale problems than you have! So my feedback might not be as relevant I wrote detailed commentary here: https://github.com/s-arash/ascent/discussions/72 Re Rust bindings and your specific comment: - Deploying Soufflé and doing FFI is much more difficult for me in practice, just in terms of the overhead to set up a working build. (I'm not going to be able to justify setting up a Soufflé ruleset for Bazel, and then adding Rust-Soufflé binding generation, etc. at my workplace.) - User-defined functors, or integrating normal data structures/functions/libraries into your Soufflé program, seems painful. If you're doing integrations with random existing systems, then reducing the friction here is essential. (In slide 16 of the talk, you can see how I embedded a constructive `Trace` type and a `GlobSet` into an actual Ascent value+lattice.) - On the other hand, you might need Soufflé's component system for structuring larger programs whereas I might not (see above GitHub discussion). Non-specifically: - Several features like generative clauses, user-defined aggregations, lattices, etc. seem convenient in practice. - I had worse performance with Soufflé than Ascent for my program for some query-planning reason that I couldn't figure out. I don't really know why; see https://github.com/souffle-lang/souffle/discussions/2557

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jitl 2 days ago | parent | prev | next [-]

For a while the Rust compiler's borrow checker "Polonius" was implemented with datalog using the `datafrog` engine. However, it appears to me that the in-tree version of polonius is moving away from datafrog (not enough of a rustc expert to say for sure which version of the borrow checker engine is in use)

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chc4 2 days ago | parent | prev [-]

CodeQL compiles to the Souffle datalog engine and I use it for static analysis. I've also used ascent for a few random side projects in Rust which is very convenient.