sqltorrent VS sql.js-httpvfs

Or even better store data as an sqlite file that is full-text-search indexed. Then you can full-text search the torrent on demand: https://github.com/bittorrent/sqltorrent

"There was that project some guy posted a while back that used a combination of sqlite and partial downloads to enable searches on a database before it was downloaded all the way."

https://github.com/bittorrent/sqltorrent

Interesting question. I looked at the source code to understand that.

SQLite knows where to look for when you open a SQLite database and you run a query, right? It just asks the underlying filesystem to provide N bytes starting from an offset using a C function, then it repeats the same operation on different portions of the file, it does its computation and everybody is happy.

The software relies on sqltorrent, which is a custom VFS for SQLite. That means that SQLite function to read data from a file stored in the filesystem is replaced by a custom function. Such custom code computes which Torrent block(s) should have the highest priority, by dividing the offset and the number of bytes that SQLite wants to read by the size of the torrent blocks. It is just a division.

See: https://github.com/bittorrent/sqltorrent/blob/master/sqltorr...

I couldn't find do these wrappers support read-only SQLite databases with HTTP range requests, like in this famous post [1]. Phiresky's wrapper supports it, but it seems to be rebuilding the whole sql.js [2], I'd rather have it as VFS on top of sqlite.org's own WASM module. I like the idea of HTTP range requests, but I don't want to run a fork, that will be unmaintained in few years.

[1]: https://news.ycombinator.com/item?id=27016630

[2]: https://github.com/phiresky/sql.js-httpvfs

Oh that’s an interesting idea. I saw someone built SQLite over HTTP with the Range header: https://phiresky.github.io/blog/2021/hosting-sqlite-database...

So presumably in a similar manner as https://github.com/phiresky/sql.js-httpvfs you could map SQLite pages to leaf torrents too and get the chunking you are looking for.

But ripgrep has to read the whole file; if your intended use case is searching a blog, I'd recommend using something which makes an index, so you don't need to download everything. For example, sql.js-httpvfs is SQLite ported to wasm, with the DB file read over HTTP. If you use FTS to make an index, it works astonishingly well for text search.

How close is Python SQLite and Datasette Lite to accessing a hosted SQL database using HTTP range requests as can be done in sql.js like https://github.com/phiresky/sql.js-httpvfs?

I put together a Pyodide-based web app where users need a few indexed queries from a 600mb SQLite database but it isn't very practical for them to download the whole thing into the browser.

https://observablehq.com/@thadk/life

You can also access sqlite databases directly from an http server that supports range requests (like s3). There are a bunch of implementations of this in different languages including Go[0] and Javascript[1].

[0]: https://github.com/psanford/sqlite3vfshttp

[1]: https://github.com/phiresky/sql.js-httpvfs

Hosting SQLite Databases on GitHub Pages" https://news.ycombinator.com/item?id=28021766 : DuckDB can query [and page] Parquet from GitHub, sql.js-httpvfs, sqltorrent, File System Access API (Chrome only so far; IDK about resource quotas and multi-GB datasets), serverless search with WASM workers

https://github.com/phiresky/sql.js-httpvfs :

> sql.js is a light wrapper around SQLite compiled with EMScripten for use in the browser (client-side).

> This repo is a fork of and wrapper around sql.js to provide a read-only HTTP-Range-request based virtual file system for SQLite. It allows hosting an SQLite database on a static file hoster and querying that database from the browser without fully downloading it.

> The virtual file system is an emscripten filesystem with some "smart" logic to accelerate fetching with virtual read heads that speed up when sequential data is fetched. It could also be useful to other applications, the code is in lazyFile.ts. It might also be useful to implement this lazy fetching as an SQLite VFS [*] since then SQLite could be compiled with e.g. WASI SDK without relying on all the emscripten OS emulation.

It doesn't have to be range requests, you could split the file instead of depending on the range requests. Essentially it's the same as the chunking instructions for hosters who have a maximum file size as is demonstrated here: https://github.com/phiresky/sql.js-httpvfs/blob/master/creat...

They left the sourcemaps in their build, so one can see the code from the Usage section of sql.js-httpvfs (https://github.com/phiresky/sql.js-httpvfs#usage) copy-pasted into App.tsx, but I didn't find any other identifying text

I'd actually guess it was just a copy-paste of the "sqlite over webworker using wasm" demo, backed by the actual sqlite of the actions https://www.awsiam.info/iam.db