raml-spec VS pg_jsonschema

Taking this concept further one could model in RAML [0] to define both the types (flat or nested) and api definitions. It's based on YAML 1.2 with enough maturity to provide capabilities such as union types, extensions, includes, user-defined facets, etc.

The AMF project [1] can be used to parse and transform to/from RAML, OpenAPI, GraphQL, and json schema. Code generation to languages of choice can be bolted on from there.

I'm using this approach to define canonical data models. Subsequent code generation scaffolds internal application integration apis, master data management (MDM) entities, and SQL/OLAP artifacts for ETL / BI purposes.

This approach keeps overall end-to-end data architecture consistent, in sync, and versioned under source control. Additionally, flat types as required by relational systems are re-used and composed into nested complex types more appropriate for apis. Metadata is layered on as needed to refine the models for system-specific needs, for example to add user-facing field groups, descriptions, and formats for BI datasets, sensitivity levels and other data security controls, business rule definitions for MDM, etc.

[0] https://github.com/raml-org/raml-spec/blob/master/versions/r...

> Do you use JSON Schema?

At one point I did, but then discovered RAML[0] and it subsumed the value of what JSON Schema provides as well as being easier to work with than OpenAPI[1]. Also, generating JSON Schema from RAML definitions has proven to be a fairly straightforward process.

The usual caveats apply... Your mileage may vary, my experiences do not speak for any others, my opinion does not detract from the value of JSON Schema, etc.

0 - https://github.com/raml-org/raml-spec/blob/master/versions/r...

1 - https://swagger.io/specification/

And lots of interesting extensions use it, like

https://github.com/tembo-io/pgmq

https://github.com/zombodb/zombodb

https://github.com/supabase/pg_jsonschema

> In other words, there is still a (lossy) translation layer, it just happens to be in the RDBMS rather than in-app.

It's not lossy if your application can guarantee a json <-> datatype roundtrip and the json is validated with jsonschema (generated by your application)

In Rust it's something like this

https://serde.rs/ to do the data type <-> json mapping

https://docs.rs/schemars/latest/schemars/ to generate jsonschema from your types

https://github.com/supabase/pg_jsonschema to validate jsonschema in your database (postgres). with this setup it's interesting (but not required) to also use https://docs.rs/jsonschema/latest/jsonschema/ to validate the schema in your application

Pretty exciting!

What about optionally validating some columns with jsonschema? Perhaps using https://github.com/supabase/pg_jsonschema - is using other postgres extensions supported in FerretDB? (if not, maybe it's feasible to incorporate the code of pg_jsonschema in FerretDB?)

I'm not currently using it, but I'm strongly considering validating json in postgres with https://github.com/supabase/pg_jsonschema - which uses the https://docs.rs/jsonschema/latest/jsonschema/ Rust crate

So I'm not sure if my feedback is valid but, I sure hope that the jsonschema crate follows the spec! Otherwise I'll never use jsonschema but instead something-not-exactly-jsonschema. In other words.. you better not break anything.

Sounds dumb, but I want JSON field schema validation. I added a JSON column for flexible data, and although I'm happy with its flexibility, I kinda hope I can validate the JSON data structure. Recently I just found an extension [1] and will try soon.

[1] https://github.com/supabase/pg_jsonschema

https://github.com/supabase/pg_jsonschema is new and looks good

Born as an excuse to play with pgx, pg_jsonschema is a solution we're exploring to allow enforcing more structure on json and jsonb typed postgres columns. Only 10 lines of code 😎