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EvgSkv
logica
Jupyter Notebook2021–2024
EvgSkv / logica

logica

Logica is a logic programming language that compiles to SQL. It runs on DuckDB, Google BigQuery, PostgreSQL and SQLite.

Data & DatabasesLanguages & Compilers
Explore on GitHubRead Hacker News discussions
8Distinct people
9Mentions
0Explicit recommenders
2.2KGitHub stars
REPOSITORY AT A GLANCE

What to know before exploring

What it is

Logica is a logic programming language that compiles to SQL. It runs on DuckDB, Google BigQuery, PostgreSQL and SQLite.

GitHub

Where it is used

No documented product use has been verified yet.

What people are saying

No recommendation phrase was found in the indexed comments.

No classified warning is attached to this page. Read the discussions before treating silence as approval.

Also in these discussions

No other repository is repeatedly linked in the same discussions.

This week on Hacker News

Nov 7–Nov 14 UTC · Direct repository links and separately labeled related project stories. Indexed through 11/14/2026, 5:04:57 PM UTC.

No direct repository links were found in the indexed HN discussions over the past seven days. Older discussions are available below.

Mentions over time

HN mentions by year9 dated mentions

Observed mentions: 2021-04-14 11:41:03 UTC to 2024-07-18 15:37:16 UTC.

012342021-01-01 00:00:00 UTC to 2022-01-01 00:00:00 UTC (exclusive): 4 mentions; 1 submissions, 3 comments20212022-01-01 00:00:00 UTC to 2023-01-01 00:00:00 UTC (exclusive): 2 mentions; 0 submissions, 2 comments20222023-01-01 00:00:00 UTC to 2024-01-01 00:00:00 UTC (exclusive): 1 mentions; 0 submissions, 1 comments2024-01-01 00:00:00 UTC to 2025-01-01 00:00:00 UTC (exclusive): 2 mentions; 0 submissions, 2 comments2024

Counts come from the repository’s dated source evidence. Index cutoff: 2026-11-02 08:16:59 UTC.

View mention counts and date ranges
UTC ranges include their start and exclude their end. Select a period to filter the source evidence.
PeriodStart (UTC)End (exclusive, UTC)MentionsSubmissionsComments
20212021-01-01 00:00:00 UTC2022-01-01 00:00:00 UTC413
20222022-01-01 00:00:00 UTC2023-01-01 00:00:00 UTC202
20232023-01-01 00:00:00 UTC2024-01-01 00:00:00 UTC101
20242024-01-01 00:00:00 UTC2025-01-01 00:00:00 UTC202

What Hacker News says

9 sources
evgskv·Jul 18, 2024
I think of Prolog as a general purpose logic programming language and Datalog to be logic programming more focused on data analysis. Data analysis is a very large area, so boundary might get blurry at times. If your data is in a relational database consider Logica - a Datalog family language that compiles to SQL and runs naturally on SQLite, Postgres, DuckDB and Google BigQuery. Easy to install, easy to play with in CoLab or any other Jupyter notebook. Works for data analysis (aggregation, filtering etc) that is commonly associated with SQL, as well as recursive logical querries commonly associalted with Logic programming per-se. Here is what it looks like for a data-analysis-ish query of finding popular baby names over time: # Count babies per year. NameCountByYear(name:, year:) += number :- BabyNames(name:, year:, number:); # For each
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year pick the most popular. TopNameByYear(year) ArgMax= name -> NameCountByYear(name:, year:); # Accumulate most popular name into a table, dropping the year. PopularName(name: TopNameByYear()); The classic grand-parent rule looks as usual: Grandparent(a, c) :- Parent(a, b), Parent(b, c); Here is a recursive program for finidng distances in a directed graph: D(a, b) Min= 1 :- Edge(a, b); D(a, b) Min= D(a, x) + D(x, b); Links to CoLabs: Grandparent, ancestor: https://colab.research.google.com/drive/1lujnnUOXsF6VrC9__jV... Distance in graph: https://colab.research.google.com/drive/1sOCODHqN0ruxZSx_L-V... Github repo: https://github.com/EvgSkv/logica
In Ask HN: What's Prolog like in 2024?
felixyz·Jul 18, 2024
TypeDb is a practical Datalog-based database system [1] (with a different syntax). TerminusDb is a project in a similar vein [2], but actually an RDF store at its core. If you want to experiment with the connections between Datalog, relational algebra, and SQL, check out the Datalog Educational System. And if you want to jump into the theory, Foundations of Databases (the "Alice book") is very thorough but relatively readable [4]! Oh, and there's a Google project, Logica, to do Datalog over Postgres databases [5]. [1]: https://typedb.com/ [2]: https://terminusdb.com/ [3]: http://www.fdi.ucm.es/profesor/fernan/des/ [4]: http://webdam.inria.fr/Alice/ [5]: https://github.com/evgskv/logica
In Ask HN: What's Prolog like in 2024?
yowlingcat·Oct 22, 2023
First of all -- I want to thank you all for robust discussion on this subthread. I've learned a lot about the experience of other folks using Prolog and where they've gotten mileage out of its unique strengths. It's been eye opening to see for sure! Part of the reason I wanted to ask this question because I had a suspicion that there may not necessarily be as large of a gap between SQL and Prolog as there may initially appear. Said another way, I wondered if there was a Prolog (or Datalog) to SQL compiler used in production. I recently stumbled upon Logica [1], which appears to based on a predecessor (Yeladog) built at Google. I don't have experience using it, so I'm not sure how complete the implementation is nor how efficient it is. I'm curious if anyone has used it before and if so, what their experience was. At first blush, it appears
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to bring the best of both worlds: the expressive power of Prolog/Datalog, combined with the standard operational tooling of SQL which is a common core dependency in many if not most production software systems. Two questions: 1) How does Datalog compare to Prolog for common problems you might use Prolog for? Any things you can do in Prolog differentially that wouldn't be as easy in Datalog and vice versa? 2) What issues might come up in system that uses a Datalog to SQL transpiler? Given that some of the answers in this thread about the efficiency of using Prolog to do constraint solving, it seems like such an approach might lose some of the efficiency that makes it so powerful in the first place. On the other hand, if it doesn't, it seems like it'd bring a killer app to SQL, which is the ability to do constraint solving in a nearly native fashion inside SQL. [1] https://github.com/EvgSkv/logica
In Using Prolog as the AST
quelltext·Apr 14, 2021
Depends on the specific SQL flavor, e.g. https://www.postgresql.org/docs/9.1/queries-with.html Logica instead seems to create tables and drop tables? https://github.com/EvgSkv/logica/blob/main/examples/Logica_e... It looks like Logica code isn't actually translated to a (large) SQL query, but Logica code is dynamically interpreted by some interpreter that calls into a SQL database as the virtual machine. Not sure what Logica really provides here. Datalog usually comes with elaborate techniques to make sure only what's really needed is calculated instead of just generating all values every fact generation "iteration".
In Logica, a novel open-source logic programming language

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