model tagging

[gregory-marton]

Associate model numbers with key-value pairs and allow people to use inner selects on the model table wherever they might have used one or more model numbers, e.g. to analyze for some iterations or to select or simulate.
#15
#48

[riastradh-probcomp]

Why limit to key-value pairs? We have a relational database here -- create a relation with generator/modelno as foreign key.

[gregory-marton]

Limits make the associated language design somewhat easier, and one can always expand it later. I'd rather have something working sooner, than something good working later.

[riastradh-probcomp]

What language design is needed?

It is already straightforward to associate a tag or a datum with each model:

create table mytag (
    generator_id integer not null,
    modelno integer not null,
    datum text not null,
    primary key(generator_id, modelno),
    foreign key(generator_id, modelno) references bayesdb_generator_model
)

(Changing the syntax for model sets to support subqueries there is easy -- I don't think that itself requires much in the way of language design.)

[gregory-marton]

That's an underlying schema change for each kind of mytag, no? This is fine from python, but from python, it's easy enough to associate the models with dictionaries on the outside and construct queries using them. If one wants to add tags from within BQL, then there should be a syntax for associating a new tag with a model, or a group of models. In your example, effectively the key is the mytag table. In my thought process, the table would be a tags table, and there would be a string key, so that users could easily produce arbitrary key-value pairs. Of course one has to decide about replace vs. append, etc.

[riastradh-probcomp]

Creating tables is something the user of a bdb can do. SQL already has a notion of defining a meaningful relation with references to other relations, adding instances to the relation, specifying the semantics of insertion vs replacement, and so on.

In any case -- can you elaborate, with illustrative examples, on what you want to do with tagging? By 'illustrative' I mean with example syntax in the language to say in a hypothetical formal way what you want to express to solve a specific problem that would be difficult or inconvenient to solve otherwise.