Simon Willison’s Weblog

Data analysis with SQLite and Python. I turned my 2hr45m workshop from PyCon into the latest official tutorial on the Datasette website. It includes an extensive handout which should be useful independently of the video itself. # 2nd July 2023, 4:48 pm

sqlean.py: Python’s sqlite3 with extensions. Anton Zhiyanov built a new Python package which bundles a fresh, compiled copy of SQLite with his SQLean family of C extensions built right in. Installing it gets you the latest SQLite—3.42.0—with nearly 200 additional functions, including things like define() and eval(), fileio_read() and fileio_write(), percentile_95() and uuid4() and many more. “import sqlean as sqlite3” works as a drop-in replacement for the module from the standard library. # 17th June 2023, 10:42 pm

Vector Search. Amjith Ramanujam provides a very thorough tutorial on implementing vector similarity search using SentenceTransformers embeddings (all-MiniLM-L6-v2) executed using sqlite-utils, then served via datasette-sqlite-vss and deployed using Fly. # 2nd June 2023, 5:02 am

SQLite 3.42.0. The latest SQLite has a tiny feature I requested on the SQLite Forum—SELECT unixepoch(’subsec’) now returns the current time in milliseconds since the Unix epoch, a big improvement on the previous recipe of select cast((julianday(’now’)—2440587.5) * 86400 * 1000 as integer)!

Also in the release: JSON5 support (JSON with multi-line strings and comments), a bunch of improvements to the query planner and CLI tool, plus various interesting internal changes. # 18th May 2023, 9:14 pm

Replacing my best friends with an LLM trained on 500,000 group chat messages (via) Izzy Miller used a 7 year long group text conversation with five friends from college to fine-tune LLaMA, such that it could simulate ongoing conversations. They started by extracting the messages from the iMessage SQLite database on their Mac, then generated a new training set from those messages and ran it using code from the Stanford Alpaca repository. This is genuinely one of the clearest explanations of the process of fine-tuning a model like this I’ve seen anywhere. # 12th April 2023, 11:01 pm

Making SQLite extensions npm install’able for Node.js, and on deno.land/x for Deno (via) Alex Garcia figured out how to get his “pip install X” trick for distributing compiled SQLite extensions to work for Node too! Now you can “npm install” 10 of his extensions, including sqlite-regex and sqlite-xsv and sqlite-http and sqlite-html and more, and attach them to a node-sqlite3 or better-sqlite3 connection. He’s bundled them for Deno too! # 29th March 2023, 10:13 pm

apple-notes-to-sqlite (via) With the help of ChatGPT I finally figured out just enough AppleScript to automate the export of my notes to a SQLite database. AppleScript is a notoriously read-only language, which is turns out makes it a killer app for LLM-assisted coding. # 9th March 2023, 6:04 am

Online gradient descent written in SQL (via) Max Halford trains an online gradient descent model against two years of AAPL stock data using just a single advanced SQL query. He built this against DuckDB—I tried to replicate his query in SQLite and it almost worked, but it gave me a “recursive reference in a subquery” error that I was unable to resolve. # 7th March 2023, 6:56 pm

djngo.com: Portable Django (via) “A 20mb executable zip file with Python 3.6 and Django 2.2. Works on Windows, Linux, MacOSX with x86_64 and aarch64 (yes, Apple M1 and Raspberry Pi).” The latest wizardry from the ecosystem surrounding the Cosmopolitan project, which provides a should-be-impossible mechanism for running the same executable on a bunch of different platforms. This utility by Ariel Núñez bundles Python and Django and SQLite, such that a Django application can become a portable executable ready to run on multiple platforms. It’s currently limited to Python 3.6 and Django 2.2 since those are the versions that run under Cosmopolitan, but I expect we’ll see more recent versions of those dependencies in the future. # 24th February 2023, 12:52 am

Introducing sqlite-vss: A SQLite Extension for Vector Search (via) This latest SQLite extension from Alex Garcia is possibly his best yet: it adds FAISS-powered vector similarity search directly to SQLite, enabling fast KNN similarity lookups against a virtual table that feels a lot like SQLite’s own built-in full text search feature. This write-up includes interactive demos using Datasette called from an Observable notebook, running similarity searches against an index of 200,000 news headlines and summaries in less than 50ms. # 10th February 2023, 10:53 pm

Making SQLite extensions pip install-able (via) Alex Garcia figured out how to bundle a compiled SQLite extension in a Python wheel (building different wheels for different platforms) and publish them to PyPI. This is a huge leap forward in terms of the usability of SQLite extensions, which have previously been pretty difficult to actually install and run. Alex also created Datasette plugins that depend on his packages, so you can now “datasette install datasette-sqlite-regex” (or datasette-sqlite-ulid, datasette-sqlite-fastrand, datasette-sqlite-jsonschema) to gain access to his custom SQLite extensions in your Datasette instance. It even works with “datasette publish --install” to deploy to Vercel, Fly.io and Cloud Run. # 6th February 2023, 7:44 pm

sqlite-jsonschema. “A SQLite extension for validating JSON objects with JSON Schema”, building on the jsonschema Rust crate. SQLite and JSON are already a great combination—Alex suggests using this extension to implement check constraints to validate JSON columns before inserting into a table, or just to run queries finding existing data that doesn’t match a given schema. # 28th January 2023, 3:50 am

sqlite-ulid. Alex Garcia’s sqlite-ulid adds lightning-fast SQL functions for generating ULIDs—Universally Unique Lexicographically Sortable Identifiers. These work like UUIDs but are smaller and faster to generate, and can be canonically encoded as a URL-safe 26 character string (UUIDs are 36 characters). Again, this builds on a Rust crate—ulid-rs—and can generate 1 million byte-represented ULIDs with the ulid_bytes() function in just 88.4ms. # 28th January 2023, 3:45 am

sqlite-fastrand. Alex Garcia just dropped three new SQLite extensions, and I’m going to link to all of them. The first is sqlite-fastrand, which adds new functions for generating random numbers (and alphanumeric characters too). Impressively, these out-perform the default SQLite random() and randomblob() functions by about 1.6-2.6x, thanks to being built on the Rust fastrand crate which builds on wyhash, an extremely fast (though not cryptographically secure) hashing function. # 28th January 2023, 3:41 am

Wildebeest (via) New project from Cloudflare, first quietly unveiled three weeks ago: “Wildebeest is an ActivityPub and Mastodon-compatible server”. It’s built using a flurry of Cloudflare-specific technology, including Workers, Pages and their SQLite-based D1 database. # 23rd January 2023, 12:03 am

Hctree Design Documentation. More detailed information on the design of the new Hctree SQLite branch. # 20th January 2023, 12:50 am

Hctree: an experimental high-concurrency database backend for SQLite (via) Really interesting new research branch from the core SQLite team. “Hctree uses optimistic row-level locking and is designed to support dozens of concurrent writers running at full-speed”—with very impressive benchmarks supporting that claim. Also two bonuses: it has a replication mechanism based on the existing SQLite sessions extension, and it bumps up the maximum size of a SQLite database from 16TiB to 1EiB (roughly one million TiB). # 20th January 2023, 12:47 am

Introducing sqlite-xsv: The Fastest CSV Parser for SQLite. Alex Garcia continues to push the boundaries of SQLite extensions. This new extension in Rust wraps the lightning fast Rust csv crate and provides a new csv_reader() virtual table that can handle regular, gzipped and zstd compressed files. # 14th January 2023, 9:54 pm

Introducing sqlite-loadable-rs: A framework for building SQLite Extensions in Rust. Alex Garcia has built a new Rust library for creating SQLite extensions—initially supporting custom scalar functions, virtual tables and table functions and with more types of extension coming soon. This looks very easy to use, partly because the documentation and examples are already delightfully thorough, especially for an initial release. # 7th December 2022, 11:08 pm

fasiha/yamanote (via) Yamanote is “a guerrilla bookmarking server” by Ahmed Fasih—it works using a bookmarklet that grabs a full serialized copy of the page—the innerHTML of both the head and body element—and passes it to the server, which stores it in a SQLite database. The files are then served with a Content-Security-Policy’: `default-src ’self’ header to prevent stored pages from fetching ANY external assets when they are viewed. # 16th November 2022, 3:48 am

JSON Changelog with SQLite (via) One of my favourite database challenges is how to track changes to rows over time. This is a neat recipe from 2018 which uses SQLite triggers and the SQLite JSON functions to serialize older versions of the rows and store them in TEXT columns. # 16th November 2022, 3:41 am

About the sqlite3 WASM/JS Subproject. SQLite now maintains an official WebAssembly build. It’s influenced by sql.js but is a fresh implementation with its own API design. It also supports Origin-Private FileSystem (OPFS)—a very new standard which doesn’t yet have wide browser support that allows websites to save and load files using a dedicated folder on the host machine. # 28th October 2022, 11:05 pm