rfcs VS libpg_query

Search it is! I could implement search that searches for exact tokens in the tools the author connected and the README, but I want to wait for anything more until EdgeDB releases its full-text search solution https://github.com/edgedb/rfcs/blob/master/text/1015-full-te...

I actually had a feature in mind where people could vote on starters they want and others could build them out and list them for free or a price. Do you think that would fit your needs and is there anything in particular you'd want to see in a feature like that?

Replied on Twitter!

> I see EdgeDB as primarily focused on transactional queries, whereas PRQL is very focused on analytical queries.

That's true to an extent currently, but we actually envisioned EdgeQL to be a capable analytical query language too. We'll release EdgeDB 2.0 in a couple of weeks and it will feature a powerful GROUP BY statement (read more about it here [1]) and in 3.0 we might ship window functions (or some equivalent).

With all that said PRQL looks cool!

[1] https://github.com/edgedb/rfcs/blob/master/text/1009-group.r...

>> We shall do better than SQL

> The EdgeQL language looks cool, and I'm sure querying via a graph structure makes certain problems easier in some use cases. However as much as people have complained about SQL, it's just so ubiquitous there needs to be a very good reason to switch away from it. Not having to write joins isn't really a good enough reason, in my opinion.

Oh, it goes much deeper than not writing joins. There's no single ORM out there that can implement a TypeScript query builder like ours, see the example in [1]. This is only possible because of EdgeQL composability, but that composability required us to rethink the entire relational foundation.

> > The true source of truth

> I'm not sure why this means EdgeDB is better. <..>

This section implies that EdgeDB's schema allows to specify a lot of meta / dynamically computed information in it. And soon your access control policies. Take a look at the work-in-progress RFC [2] [3] to see how this is more powerful, then say, Postgres' row level security.

> > Not just a database server

> It sounds like they have a solid client, which is awesome.

Also lightweight connections to the DB so that you can have thousands of concurrent ones without load balancers, built-in schema migrations engine, and many other things. In fact we have so much that it's challenging what to even highlight in a blog post like the 1.0 announcement.

> Cloud-ready database APIs

> This used to be true, but is definitely no longer true. Cloud-native databases are everywhere and incredibly common. See any major cloud, https://www.cockroachlabs.com/, or any of the tons of other database solutions.

Not to pick on CockroachDB (they have an amazing product and company, we love them), but you should benchmark local install of Postgres and Cockroach to see yourself that scalability still has a significant cost in performance.

[1] https://www.edgedb.com/blog/edgedb-1-0#not-just-a-database-s...

[2] https://github.com/edgedb/rfcs/pull/49

[3] https://github.com/edgedb/rfcs/pull/50/files

EdgeQL is getting support for generic partitioning/aggregating `GROUP` very soon [1], so we are giving some love to the analytical side of things too :-)

We definitely need more collective effort put into "Better SQL", so PRQL is a welcome sight!

[1] https://github.com/edgedb/rfcs/blob/21e581a188715c6ff82944b6...

This in combination with [pg_query](https://github.com/pganalyze/libpg_query) could be a very powerful combination that allows writing generic static analyzers.

It's true that the core PG code isn't written in a modular way that's friendly to integration piecemeal in other projects (outside of libpq).

For THIS PARTICULAR case, the pganalyze team has actually extracted out the parser of PG for including in your own projects:

https://github.com/pganalyze/libpg_query

#. 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

Generally I agree that this would be great to have, and Postgres does have a set of libraries it already maintains as part of the main source tree (i.e. libpq, etc), and there is a shared set of code between the backend and the "frontend" (https://github.com/postgres/postgres/tree/master/src/common). So theoretically you could imagine the parser moving into that shared code portion, sharing code but not necessarily requiring linking to a library from the backend.

However, the challenge from what I've understood from past conversations with some folks working on Postgres core is that the parser is currently heavily tied into the backend - note the parser isn't just the scan.l/gram.y file, but also the raw parse node structs that it outputs. You can see how many files we pull in from the main tree that are prefixed with "src_backend": https://github.com/pganalyze/libpg_query/tree/15-latest/src/...

Further, there isn't a canonical way to output node trees into a text format today in core, besides the rather hard to work with output of debug_print_parse - there have been discussions on -hackers to potentially utilize JSON here, which may make this a bit easier. Note that in libpg_query we currently use Protobuf (but used to use JSON), which does have the benefit of getting auto-generated structs in the language bindings - but Protobuf is not used in core Postgres at all today.

All in all, I think there is some upstream interest, but its not clear that this is a good idea from a maintainability perspective.

Neat project!

Just in case its helpful to you, I (together with colleagues at pganalyze) maintain pg_query, which packages the Postgres parser as a library: https://github.com/pganalyze/libpg_query

Might be useful to include in your product as a way to run a quick syntax check on the query output by the LLM, without actually connecting to the database and causing an error in the logs.

I like that everyone is trying to make something like SQL that reads more naturally to them. More alternatives is good! SQL is a widely accepted standard, and has strictly defined and super broadly accepted semantics.

As someone who has written quite a few half-baked-for-general-use but fit-for-purpose SQL generator utilities over the years, I'll suggest that if you intend for a novel syntax to be a general SQL replacement then being isomorphic to SQL would massively increase usefulness and uptake:

1. novel syntax to SQL; check! Now novel syntax works with all the databases!

2. any valid SQL to novel syntax; a bit harder, but I'd start by using a SQL parser like https://github.com/pganalyze/libpg_query and translating the resulting AST into the novel syntax.

3. novel syntax to SQL back to novel syntax is idempotent; a nice side effect is a validator/formatter for "novel syntax"

4. SQL to novel syntax back to SQL is idempotent; a nice side effect is a validator/formatter for SQL, which would be awesome. (See also https://go.dev/blog/gofmt, which is where I learned this "round trip as formatter" trick.)

I don't mean for this to sound negative, and I know that 2, 3, and 4 are kind of hard. Thank you for building prql!

I feel like https://github.com/pganalyze/libpg_query should be the default choice for anything that needs a SQL parser. PL/SQL parsing is included there.

Rules are enforced by parsing statements into a syntax tree and checking all of the nodes against the provided rules. Statement parsing is done through bindings to the excellent libpg_query library, which uses Postgres's own statement parser to generate the syntax tree.

libpg_query extracts the parser (written in C) from the postgres project and packages it as a stand-alone library. This library is wrapped in other languages by other projects like: