[feat] BigQuery Support

[z3z1ma]

It seems there are very few blockers for BigQuery support. I believe its just the SQL generation which uses some non ANSI casting syntax ::.

Congrats on the 3.0 upgrade, looks nice!

[z3z1ma]

Oh actually this seems to be the bottleneck:
https://github.com/GClunies/Reflekt/blob/main/reflekt/warehouse.py#L89

I would consider, specifically for dbt users at least since I don't see Warehouse used anywhere else -- we piggyback off of existing dbt infra using something like dbt-core-interface which can be vendored.

[GClunies]

@z3z1ma Yup, agree this should not be too hard. I've never used BQ so that's the main blocker! 😆 Open to help here!

dbt-core-interface looks interesting, but its not clear to me how it helps here? Can you elaborate for me? Currently, Warehouse is used in dbt.py so that the DbtBuilder class can query the DWH for a matching table and columns as it parses each schema.

Note - in the future, reflekt could build other types of data artifacts (e.g., Looker views, etc). The end user might not use dbt at all in this scenario.

[GClunies]

Addressed in #105. FYI @z3z1ma

[z3z1ma]

Awesome @GClunies 💯 I will check it out