pg_similarity

set of functions and operators for executing similarity queries

Data & Databases

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What it is

set of functions and operators for executing similarity queries

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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.

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Observed mentions: 2019-10-20 04:51:28 UTC to 2023-02-07 19:25:13 UTC.

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Period	Start (UTC)	End (exclusive, UTC)	Mentions	Comments
2019	2019-01-01 00:00:00 UTC	2020-01-01 00:00:00 UTC	1	1
2020	2020-01-01 00:00:00 UTC	2021-01-01 00:00:00 UTC	0	0
2021	2021-01-01 00:00:00 UTC	2022-01-01 00:00:00 UTC	1	1
2022	2022-01-01 00:00:00 UTC	2023-01-01 00:00:00 UTC	0	0
2023	2023-01-01 00:00:00 UTC	2024-01-01 00:00:00 UTC	1	1

What Hacker News says

3 sources

btown·Feb 7, 2023

Note that pgvector isn't supported on any of the large cloud providers' hosted Postgres offerings, other than Supabase. https://github.com/pgvector/pgvector#hosted-postgres has instructions on how to add your voice to request it to be added! (It does seem that the ancient https://github.com/eulerto/pg_similarity is supported by RDS and Google Cloud - but it's hard to tell whether attention was paid to its performance characteristics with nearly the rigor that pgvector seems to have been designed.)

In Supabase Clippy – ChatGPT for Supabase Docs

hardwaresofton·Aug 9, 2021

While I don't doubt that you know your usecase and weighed/tried the option. > Postgres search is essentially an easier to use regex engine. I'm not sure exactly what you meant to convey here, but if you're searching with LIKE or `~` you're not doing Postgres's proper Full Text Search. You should be dealing with tsvectors[0] > As soon as you need multiple languages Postgres FTS supports multiple languages and you can create your own configurations[1] > advanced autocomplete I'm not sure what "advanced" autocomplete is but you can get pretty fast trigram searches going[2] (back to LIKE/ILIKE here but obviously this is an isolated usecase). In the end I'd expect auto complete results to actually not hit your DB most of the time (maybe I'm naive but that feels like a caching > cache invalidation > cache pushdown problem to me) > misspelling

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detection pg_similarity_extension[3] might be of some help here, but it may require some wrangling. > large documents, large datasets, PG has TOAST[4], and obviously can scale (maybe not necessarily great at it) -- see pg_partman/Timescale/Citus/etc. > custom scoring Postgres only has basic ranking features[5], but you can write your own functions and extend it of course. Solr/ES are definitely the right tools for the job (tm) when the job is search, but you can get surprisingly far with Postgres. I'd argue that many usecases actually don't want/need a perfect full text search solution -- it's often minor features that turn into overkill fests and ops people learning/figuring out how to properly manage and scale an ES cluster and falling into pitfalls along the way. [0]: https://www.postgresql.org/docs/current/textsearch-intro.htm... [1]: https://www.postgresql.org/docs/current/textsearch-intro.htm... [2]: https://about.gitlab.com/blog/2016/03/18/fast-search-using-p... [3]: https://github.com/eulerto/pg_similarity [4]: https://www.postgresql.org/docs/current/storage-toast.html [5]: https://www.postgresql.org/docs/9.5/textsearch-controls.html...

In Official Elasticsearch Python library no longer works with open-source forks

faizshah·Oct 20, 2019

After using this, metaphone and other interesting similarity metrics for data cleaning in OpenRefine, I was looking for a python library that had these sorts of similarity metrics. I found this quite interesting (and comprehensive) project that includes regular string distance (fuzzy search) methods, fingerprinting methods and a huge number of phonetic metrics including 7 different soundex methods: https://github.com/chrislit/abydos A few others worth mentioning: Scala: https://github.com/rockymadden/stringmetric Java/Scala: https://github.com/vickumar1981/stringdistance Postgres: https://github.com/eulerto/pg_similarity R: https://github.com/markvanderloo/stringdist Clojure: https://github.com/Yomguithereal/clj-fuzzy

In Soundex – a phonetic algorithm for indexing names by sound