Dbt: support persist_docs on all plugins

[drewbanin]

Feature

Meta-issue tracking the implementation of this feature for all plugins:

• [x] pg/redshift https://github.com/fishtown-analytics/dbt/issues/2333
• [x] snowflake https://github.com/fishtown-analytics/dbt/issues/2334
• [x] bigquery https://github.com/fishtown-analytics/dbt/issues/2335

[ashley-sherwood]

+1!

Snowflake does offers dollar-quoted string constants which ensure that an arbitrary string is taken literally $$they look like this, it's pretty cool, and the ' will be literal$$

https://docs.snowflake.net/manuals/sql-reference/data-types-text.html#dollar-quoted-string-constants

Is that helpful here?

[drewbanin]

Hey @ashley-sherwood - that's _incredibly_ helpful! I didn't know you could do this on Snowflake :)

Looks like something similar is possible on Redshift/Postgres too: https://www.postgresql.org/docs/current/sql-syntax-lexical.html#SQL-SYNTAX-CONSTANTS

I think this is enough info to unblock this issue for sure. Are you interested in submitting a PR for Snowflake? Would be happy to help however I can!

Thanks for the info!

[drewbanin]

persist docs is shipping for all core plugins (at the relation and column level, where possible/applicable) in v0.17.0 🎉