Curious sortkey override behavior

[ryanaustincarlson]

Describe the bug

We’ve run into an issue with defining sort config parameters in multiple places if both values are lists.

If…

1. a default sort config is defined in the dbt_project;
2. a model-specific sort parameter is defined; and
3. both sort configurations are lists

then the resulting sort key is a concatenation of all of the keys, at least on Redshift (not sure how platform-dependent this might be).

Steps To Reproduce

Define a list of sort keys on a particular path in dbt_project

models:
  project_name:
    events:
      sort: ['occurred_at', 'client']

Then, create a new model in that path (e.g., project_name/events/cool_events_facts.sql) and redefine sort-keys

{{
    config(
        sort=['day_of_week','version']
    )
}}

When the model is built, the resulting SQL concatenates all four values, something like this (on Redshift):

create table
    events.cool_events_facts
    compound sortkey(day_of_week,version,occurred_at,client)
as (
    select *
    from whatever
);

Expected behavior

My expectation is that the model-specific sort param overrides those in dbt_project, which is what happens when a string literal is used instead of a list.

Screenshots and log output

LMK if you need any more info!

System information

Which database are you using dbt with?

• postgres
• redshift
• bigquery
• snowflake
• other (specify: ____________)

The output of dbt --version:

installed version: 0.15.0
   latest version: 0.15.0

Up to date!

The operating system you're using:

macOS v10.14.6

The output of python --version:

Python 3.7.6

Additional context

Our current workaround is to define the model-specific sort params in dbt_project, which seems to override as expected.

[drewbanin]

Thanks for the report @ryanaustincarlson! I was able to reproduce this pretty easily, but it was tough getting to the bottom of the actual issue!

I started working on a fix for this over here: #2062. This PR should be shipped for our next patch release, v0.15.2 (or possibly 0.16.0).

Edit: This will be going out in the 0.16.0 Barbara Gittings release

[drewbanin]

Fixed by #2062