wa-sqlite VS litefs

The word on the street is that https://github.com/rhashimoto/wa-sqlite is nearly production ready, closing in on the neat 1.0.0 release, with its IDBBatchAtomic engine highly recommended at https://www.powersync.com/blog/sqlite-persistence-on-the-web. You can try out the benchmark https://rhashimoto.github.io/wa-sqlite/demo/benchmarks.html.

And the other contestant is Dexie, stable https://dexie.org/.

If you were to branch into a new venture today, which one would you pick? And why?

It seems indeed very nice, the examples are clear and everything works from async. I tried with Deno, and now experimenting with my own VFS.

It does seem to suffer from maintainer problems too though, and I don't blame Roy Hashimoto for that. I wouldn't want to maintain such an obvious wrapper when it should be a task for SQLite's team to upstream the changes.

Roy Hashimoto doesn't want to maintain it as an NPM package for instance, as it is just an experiment: https://github.com/rhashimoto/wa-sqlite/issues/12

"Low traffic is a happy place - I don't have any motivation to mess with that."

This is the WASM blob and it's 1.1 MB uncompressed. https://github.com/rhashimoto/wa-sqlite/blob/master/dist/wa-.... No issues - it's cached by cloudflare.

We're using IndexedDB. Here's a writeup on alternatives https://github.com/rhashimoto/wa-sqlite/issues/85 and a benchmark https://rhashimoto.github.io/wa-sqlite/demo/benchmarks.html

I have a genuine appreciation for how Linear has built this. We have had to build something similar for our note taking application (Reflect). It is very tricky to do and I wish there was more research on this.

In my opinion, what we need is:

1) A client-side performant SQLite database that supports live queries. I.e. you can automatically re-render the page when the queries change. That way your database can drive the UI and be the source of truth in regards to what's displayed on the screen.

2) A separate realtime syncing protocol that syncs database state to client state.

And ideally this is all open source, and that these two endeavors are not coupled tightly.

[1] Wa-sqlite is the best (imo) client-side db - better than than the official Sqlite WASM build (for now) because it had a indexeddb fallback for browsers that aren't the cutting edge Chrome.

[2] cr-sqlite is an interesting project using CRDTs to sync state around. However I still believe that for many production use-cases you want a ultimate server source of truth.

[3] Replicache is still the best closed source solution I know of.

[1] - https://github.com/rhashimoto/wa-sqlite

[2] https://github.com/rhashimoto/wa-sqlite/discussions/63

Firstly, LiteJob's reliance on SQLite inherently restricts its horizontal scaling capabilities. Unlike other databases, SQLite is designed for single-machine use, making it challenging to distribute workload across multiple servers. This can certainly be done using novel technologies like LiteFS, but it is far from intuitive.

Im curious to know if others have tried out Turso or LiteFS or any of the newer edge db providers that are popping up in 'real world' applications and what your experiences have been?

Author here. I think we could have set better expectations with our Postgres docs. It wasn't meant to be a managed service but rather some tooling to help streamline setting up a database and replicas. I'm sorry about the troubles you've had and that it's come off as us being disingenuous. We blog about things that we're working on and find interesting. It's not meant say that we've figured everything out but rather this is what we've tried.

As for this post, it's not managed SQLite but rather an open source project called LiteFS [1]. You can run it anywhere that runs Linux. We use it in few places in our infrastructure and found that sharing the underlying database for internal tooling was really helpful for that use case.

[1]: https://github.com/superfly/litefs

#. SQLite WAL mode

From https://www.sqlite.org/isolation.html https://news.ycombinator.com/item?id=32247085 :

> [sqlite] WAL mode permits simultaneous readers and writers. It can do this because changes do not overwrite the original database file, but rather go into the separate write-ahead log file. That means that readers can continue to read the old, original, unaltered content from the original database file at the same time that the writer is appending to the write-ahead log

#. superfly/litefs: aFUSE-based file system for replicating SQLite https://github.com/superfly/litefs

#. sqldiff: https://www.sqlite.org/sqldiff.html https://news.ycombinator.com/item?id=31265005

#. dolthub/dolt: https://github.com/dolthub/dolt

> Dolt can be set up as a replica of your existing MySQL or MariaDB database using standard MySQL binlog replication. Every write becomes a Dolt commit. This is a great way to get the version control benefits of Dolt and keep an existing MySQL or MariaDB database.

#. pganalyze/libpg_query: https://github.com/pganalyze/libpg_query :

> C library for accessing the PostgreSQL parser outside of the server environment

#. Ibis + Substrait [ + DuckDB ]

> ibis strives to provide a consistent interface for interacting with a multitude of different analytical execution engines, most of which (but not all) speak some dialect of SQL.

> Today, Ibis accomplishes this with a lot of help from `sqlalchemy` and `sqlglot` to handle differences in dialect, or we interact directly with available Python bindings (for instance with the pandas, datafusion, and polars backends).

> [...] `Substrait` is a new cross-language serialization format for communicating (among other things) query plans. It's still in its early days, but there is already nascent support for Substrait in Apache Arrow, DuckDB, and Velox.

#. benbjohnson/postlite: https://github.com/benbjohnson/postlite

> postlite is a network proxy to allow access to remote SQLite databases over the Postgres wire protocol. This allows GUI tools to be used on remote SQLite databases which can make administration easier.

> The proxy works by translating Postgres frontend wire messages into SQLite transactions and converting results back into Postgres response wire messages. Many Postgres clients also inspect the pg_catalog to determine system information so Postlite mirrors this catalog by using an attached in-memory database with virtual tables. The proxy also performs minor rewriting on these system queries to convert them to usable SQLite syntax.

> Note: This software is in alpha. Please report bugs. Postlite doesn't alter your database unless you issue INSERT, UPDATE, DELETE commands so it's probably safe. If anything, the Postlite process may die but it shouldn't affect your database.

#. > "Hosting SQLite Databases on GitHub Pages" (2021) re: sql.js-httpvfs, DuckDB https://news.ycombinator.com/item?id=28021766

#. awesome-db-tools https://github.com/mgramin/awesome-db-tools

LiteFS works sorta like that. It provides read replicas on all your application servers so you can use it just like vanilla SQLite for queries.

Write transactions have to occur on the primary node but that's mostly because of latency. SQLite operates in serializable isolation so it only allows one transaction at a time. If you wanted to have all nodes write then you'd need to acquire a lock on one node and then update it and then release the lock. We actually allow this on LiteFS using something called "write forwarding" but it's pretty slow so I wouldn't suggest it for regular use.

We're adding an optional a query API over HTTP [1] soon as well. It's inspired by Turso's approach. That'll let you issue one or more queries in a batch over HTTP and they'll be run in a single transaction.

[1]: https://github.com/superfly/litefs/issues/326

Basically, LiteFS: https://github.com/superfly/litefs

And then some load balancer cleverness that reroutes writes to a specific VM: https://fly.io/blog/globally-distributed-postgres/

But my guess is they'll have an alternate implementation or something like LiteFS in Deno Deploy that will make this substantially more interesting when running in the Cloud.