@wei I think this depends more on the external communication architecture of the surrounding system than on the fact that it uses Datomic. We have an RPC-style architecture, in which each endpoint has its Plumatic schema - I wish I could use spec for that, but I need coercion which is an unfortunate conseaquence of using JSON a a format. A GraphQL-style may have a spec per write handler - and maybe some of it is either derived from the database schema or colocated with the schema definition.

@val_waeselynck Can you not use custom conformers for coercion?

e.g. https://gist.github.com/Deraen/6c686358da62e8ed4b3d19c82f3e786a

@val_waeselynck would you use clojure.spec instead of Plumatic if you were starting your app today?

@gws any special configuration needed? I’m trying to cram free trasactor onto a raspberry pi

@val_waeselynck Hi Val, do you known if there’s a tool to visualize a Datomic schema ?

@gphilipp out of curiosity, what sort of visualisation would you be looking for?

the Datomic console gives you a tree for the schema

Something like this : https://github.com/Datomic/mbrainz-sample/blob/master/relationships.png

It would probably rely on parsing key names because you can't enforce refs types.

@gphilipp I don't use one (controversially, I derive schema from code) but I think @robert-stuttaford has some tools for that

@gphilipp i built https://github.com/Cognician/datomic-doc to help with exploring and documenting schema. no pretty diagrams, i’m afraid!

@robert-stuttaford This looks nice, I’ll take a look

@gphilipp interesting. Datomic doesn’t have a way to define which attributes belong to which entity (which would be required to auto-generate a diagram like mbrainz), BUT namespace in attribute keywords kind of play that role

So if you are strict on always using the same convention for attribute names, namely :entity-name/property-name, then I guess you could auto-generate this diagram

Sounds like a good opportunity for a PR to Cognician/datomic-doc if @robert-stuttaford is keen 😛

I am not sure whether :entity-name/property-name for attributes is a convention with Datomic though

It just seems to be from what I’ve read/seen thusfar

@hmaurer it's a loose convention. But it will never be a solid convention because the openness of entities is desirable

@favila That’s what I thought. So long as it is somewhat widespread I guess a visualisation based on that convention could make sense

Better would be to think of the namespaces as corresponding to problem domain (i.e. attributes that are meant to be together) or even revision (e.g. :x.y.v2)

it just happens that most of the time these correspond to entity instances also

@hmaurer you will probably want to share some attributes across several entity types

unless there's a higher-level schema encoded somewhere I don't think those visualizations can be automatic

another wrinkle is that you can have multiple, independent schemas overlaying each other

@hmaurer note that attributes are entities themselves, and you can use Datomic to annotate them with type information

To give some context, I’m trying to grasp Simulant schema for a POC at work https://github.com/Datomic/simulant/blob/master/resources/simulant/schema.edn. I just found out that @stuarthalloway had made a diagram out of it https://github.com/Datomic/simulant/wiki/Schema-diagram !

is [com.datomic/clj-client "0.8.606"] still the latest version for the client library? it was released on 27-Nov-2016, seems a bit old

@hmaurer @gphilipp PRs most welcome 🙂

@val_waeselynck do you think it would make sense to then think of namespace in Datomic attributes as denotating “traits”?

In the sense that they group attributes relating to a particular “trait” of an entity

if that makes any sense

@favila oh, I see.

Are there special limitations to using datomic from Java?

Just wondering, if the Java API exposes "all there is to it"

Anybody knows if there are plans from Cognitect to offer "Datomic as a Service" ?

Hi! Is it possible to configure the path to storage files when running the transactor in “dev” mode?

Yes. It's not in transactor.properties?